Start rewriting backend to use notmuch

Signed-off-by: Matthias Beyer <mail@beyermatthias.de>

14 files changed, 176 insertions, 1214 deletions

diff --git a/doc/src/05100-lib-mails.md b/doc/src/05100-lib-mails.md
index 9a42a47a..b108f364 100644
--- a/doc/src/05100-lib-mails.md
+++ b/doc/src/05100-lib-mails.md
@@ -1,14 +1,10 @@
-## libimagmails
+## libimagmail
 
-The mail library implements everything that is needed for being used to
-implement a mail reader (MUA).
+This library implements an integration from notmuch for imag.
 
-It therefor provides reading mailboxes, getting related content or mails, saving
-attachments to external locations, crafting new mails and responses,...
+The library does not (yet) provide functionality to alter the database of
+notmuch and maybe never will.
 
-It also offers, natively, ways to search for mails (which are represented as
-imag entries).
-
-For more information on the domain of the `imag-mail` command, look at the
-documentation of the @sec:modules:mails module.
+It creates one imag entry for one notmuch message id. It only stores the message
+id in the entry, all other data can be fetched from notmuch at runtime.
 
diff --git a/lib/domain/libimagmail/Cargo.toml b/lib/domain/libimagmail/Cargo.toml
index e0b1a891..daedf129 100644
--- a/lib/domain/libimagmail/Cargo.toml
+++ b/lib/domain/libimagmail/Cargo.toml
@@ -27,8 +27,7 @@ mailparse = "0.8.0"
 filters = "0.3.0"
 failure = "0.1.5"
 resiter = "0.4.0"
-serde = "1.0.94"
-serde_derive = "1.0.94"
+notmuch = "0.6"
 
 libimagstore      = { version = "0.10.0", path = "../../../lib/core/libimagstore" }
 libimagerror      = { version = "0.10.0", path = "../../../lib/core/libimagerror" }
diff --git a/lib/domain/libimagmail/src/config.rs b/lib/domain/libimagmail/src/config.rs
deleted file mode 100644
index 4c59cb87..00000000
--- a/lib/domain/libimagmail/src/config.rs
+++ /dev/null
@@ -1,131 +0,0 @@
-//
-// imag - the personal information management suite for the commandline
-// Copyright (C) 2015-2020 Matthias Beyer <mail@beyermatthias.de> and contributors
-//
-// This library is free software; you can redistribute it and/or
-// modify it under the terms of the GNU Lesser General Public
-// License as published by the Free Software Foundation; version
-// 2.1 of the License.
-//
-// This library is distributed in the hope that it will be useful,
-// but WITHOUT ANY WARRANTY; without even the implied warranty of
-// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-// Lesser General Public License for more details.
-//
-// You should have received a copy of the GNU Lesser General Public
-// License along with this library; if not, write to the Free Software
-// Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
-//
-
-use std::path::PathBuf;
-
-/// A struct representing a full mail configuration, required for working with this library
-///
-/// For convenience reasons, this implements Serialize and Deserialize, so it can be fetched from a
-/// configuration file for example
-///
-/// # TODO
-///
-/// Figure out how to use handlebars with variables on this. Right now the support for that is not
-/// implemented yet.
-///
-#[derive(Serialize, Deserialize, Debug)]
-pub struct MailConfig {
-    default_account  : String,
-    accounts         : Vec<MailAccountConfig>,
-    fetchcommand     : MailCommand,
-    postfetchcommand : Option<MailCommand>,
-    sendcommand      : MailCommand,
-    postsendcommand  : Option<MailCommand>,
-}
-
-impl MailConfig {
-    pub fn default_account(&self) -> &String {
-        &self.default_account
-    }
-
-    pub fn accounts(&self) -> &Vec<MailAccountConfig> {
-        &self.accounts
-    }
-
-    pub fn account(&self, name: &str) -> Option<&MailAccountConfig> {
-        self.accounts()
-            .iter()
-            .find(|a| a.name == name)
-    }
-
-    pub fn fetchcommand(&self) -> &MailCommand {
-        &self.fetchcommand
-    }
-
-    pub fn postfetchcommand(&self) -> Option<&MailCommand> {
-        self.postfetchcommand.as_ref()
-    }
-
-    pub fn sendcommand(&self) -> &MailCommand {
-        &self.sendcommand
-    }
-
-    pub fn postsendcommand(&self) -> Option<&MailCommand> {
-        self.postsendcommand.as_ref()
-    }
-
-    pub fn fetchcommand_for_account(&self, account_name: &str) -> &MailCommand {
-        self.accounts()
-            .iter()
-            .find(|a| a.name == account_name)
-            .and_then(|a| a.fetchcommand.as_ref())
-            .unwrap_or_else(|| self.fetchcommand())
-    }
-
-    pub fn postfetchcommand_for_account(&self, account_name: &str) -> Option<&MailCommand> {
-        self.accounts()
-            .iter()
-            .find(|a| a.name == account_name)
-            .and_then(|a| a.postfetchcommand.as_ref())
-            .or_else(|| self.postfetchcommand())
-    }
-
-    pub fn sendcommand_for_account(&self, account_name: &str) -> &MailCommand {
-        self.accounts()
-            .iter()
-            .find(|a| a.name == account_name)
-            .and_then(|a| a.sendcommand.as_ref())
-            .unwrap_or_else(|| self.sendcommand())
-    }
-
-    pub fn postsendcommand_for_account(&self, account_name: &str) -> Option<&MailCommand> {
-        self.accounts()
-            .iter()
-            .find(|a| a.name == account_name)
-            .and_then(|a| a.postsendcommand.as_ref())
-            .or_else(|| self.postsendcommand())
-    }
-
-}
-
-/// A configuration for a single mail accounts
-///
-/// If one of the keys `fetchcommand`, `postfetchcommand`, `sendcommand` or `postsendcommand` is
-/// not available, the implementation of the `MailConfig` will automatically use the global
-/// configuration if applicable.
-#[derive(Serialize, Deserialize, Debug)]
-pub struct MailAccountConfig {
-    pub name             : String,
-    pub outgoingbox      : PathBuf,
-    pub draftbox         : PathBuf,
-    pub sentbox          : PathBuf,
-    pub maildirroot      : PathBuf,
-    pub fetchcommand     : Option<MailCommand>,
-    pub postfetchcommand : Option<MailCommand>,
-    pub sendcommand      : Option<MailCommand>,
-    pub postsendcommand  : Option<MailCommand>,
-}
-
-#[derive(Serialize, Deserialize, Debug)]
-pub struct MailCommand {
-    command: String,
-    env: Vec<String>,
-    args: Vec<String>,
-}
-
diff --git a/lib/domain/libimagmail/src/fetch.rs b/lib/domain/libimagmail/src/fetch.rs
deleted file mode 100644
index fa7106d5..00000000
--- a/lib/domain/libimagmail/src/fetch.rs
+++ /dev/null
@@ -1,117 +0,0 @@
-//
-// imag - the personal information management suite for the commandline
-// Copyright (C) 2015-2020 Matthias Beyer <mail@beyermatthias.de> and contributors
-//
-// This library is free software; you can redistribute it and/or
-// modify it under the terms of the GNU Lesser General Public
-// License as published by the Free Software Foundation; version
-// 2.1 of the License.
-//
-// This library is distributed in the hope that it will be useful,
-// but WITHOUT ANY WARRANTY; without even the implied warranty of
-// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-// Lesser General Public License for more details.
-//
-// You should have received a copy of the GNU Lesser General Public
-// License along with this library; if not, write to the Free Software
-// Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
-//
-
-use config::MailConfig;
-
-pub struct MailFetcher<'a> {
-    config: &'a MailConfig,
-    account_name_to_fetch: Option<String>,
-    boxes: Vec<String>,
-
-    rescan_maildirs: bool,
-}
-
-impl MailFetcher {
-    pub fn new(config: &MailConfig) -> Self {
-        MailFetcher {
-            config,
-            account_name_to_fetch: None,
-            rescan_maildirs: false
-        }
-    }
-
-    pub fn fetch_account(mut self, name: String) -> Self {
-        self.account_name_to_fetch = Some(name);
-        self
-    }
-
-    pub fn fetch_box(mut self, name: String) -> Self {
-        self.boxes.push(name);
-        self
-    }
-
-    pub fn fetch_boxes<I>(mut self, names: I) -> Self
-        where I: IntoIterator<Item = String>
-    {
-        self.boxes.append(names.into_iter().collect())
-        self
-    }
-
-    pub fn rescan_maildirs(mut self, b: bool) -> Self {
-        self.rescan_maildirs = b;
-        self
-    }
-
-    pub fn run(&self, store: &Store) -> Result<()> {
-        let fetchcommand = match self.account_name_to_fetch {
-            Some(name) => self.config.fetchcommand_for_account(name),
-            None       => self.confnig.fetchcommand(),
-        };
-
-        let postfetchcommand = match self.account_name_to_fetch {
-            Some(name) => self.config.postfetchcommand_for_account(name),
-            None       => self.confnig.postfetchcommand(),
-        };
-
-        let account = config
-            .account(self.account_name_to_fetch)
-            .ok_or_else(|| format_err!("Account '{}' does not exist", self.account_name_to_fetch))?;
-
-        if fetchcommand.contains(" ") {
-            // error on whitespace in command
-        }
-
-        if postfetchcommand.contains(" ") {
-            // error on whitespace in command
-        }
-
-        // fetchcommand
-
-        let mut output = Command::new(fetchcommand)
-            // TODO: Add argument support
-            // TODO: Add support for passing config variables
-            // TODO: Add support for passing environment
-            .args(self.boxes)
-            .wait_with_output()
-            .context("Mail fetching")?;
-
-        write!(rt.stdout(), "{}", output.stdout)?;
-        write!(rt.stderr(), "{}", output.stderr)?;
-
-        // postfetchcommand
-
-        let output = Command::new(postfetchcommand)
-            // TODO: Add argument support
-            // TODO: Add support for passing config variables
-            .wait_with_output()
-            .context("Post 'Mail fetching' command")?;
-
-        write!(rt.stdout(), "{}", output.stdout)?;
-        write!(rt.stderr(), "{}", output.stderr)?;
-
-        if self.rescan_maildirs {
-            // scan
-            // account.maildirroot
-            // recursively for new mail and store them in imag
-        }
-    }
-
-}
-
-
diff --git a/lib/domain/libimagmail/src/iter.rs b/lib/domain/libimagmail/src/iter.rs
deleted file mode 100644
index bba6b690..00000000
--- a/lib/domain/libimagmail/src/iter.rs
+++ /dev/null
@@ -1,83 +0,0 @@
-//
-// imag - the personal information management suite for the commandline
-// Copyright (C) 2015-2020 Matthias Beyer <mail@beyermatthias.de> and contributors
-//
-// This library is free software; you can redistribute it and/or
-// modify it under the terms of the GNU Lesser General Public
-// License as published by the Free Software Foundation; version
-// 2.1 of the License.
-//
-// This library is distributed in the hope that it will be useful,
-// but WITHOUT ANY WARRANTY; without even the implied warranty of
-// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-// Lesser General Public License for more details.
-//
-// You should have received a copy of the GNU Lesser General Public
-// License along with this library; if not, write to the Free Software
-// Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
-//
-
-use failure::Fallible as Result;
-use failure::ResultExt;
-use failure::Error;
-use failure::err_msg;
-
-use libimagstore::iter::get::StoreGetIterator;
-use libimagstore::store::FileLockEntry;
-
-use crate::mail::Mail;
-
-pub struct MailIterator<'a> {
-    inner: StoreGetIterator<'a>,
-    ignore_ungetable: bool,
-}
-
-impl<'a> MailIterator<'a> {
-    pub fn new(sgi: StoreGetIterator<'a>) -> Self {
-        MailIterator { inner: sgi, ignore_ungetable: true }
-    }
-
-    pub fn ignore_ungetable(mut self, b: bool) -> Self {
-        self.ignore_ungetable = b;
-        self
-    }
-}
-
-pub trait IntoMailIterator<'a> {
-    fn into_mail_iterator(self) -> MailIterator<'a>;
-}
-
-impl<'a> IntoMailIterator<'a> for StoreGetIterator<'a> {
-    fn into_mail_iterator(self) -> MailIterator<'a> {
-        MailIterator::new(self)
-    }
-}
-
-impl<'a> Iterator for MailIterator<'a> {
-    type Item = Result<FileLockEntry<'a>>;
-
-    fn next(&mut self) -> Option<Self::Item> {
-        while let Some(n) = self.inner.next() {
-            match n {
-                Ok(Some(fle)) => {
-                    match fle.is_mail().context("Checking whether entry is a Mail").map_err(Error::from) {
-                        Err(e)    => return Some(Err(e)),
-                        Ok(true)  => return Some(Ok(fle)),
-                        Ok(false) => continue,
-                    }
-                },
-
-                Ok(None) => if self.ignore_ungetable {
-                    continue
-                } else {
-                    return Some(Err(err_msg("Failed to get one entry")))
-                },
-
-                Err(e) => return Some(Err(e)),
-            }
-        }
-
-        None
-    }
-}
-
diff --git a/lib/domain/libimagmail/src/lib.rs b/lib/domain/libimagmail/src/lib.rs
index 913acfc9..010ec10c 100644
--- a/lib/domain/libimagmail/src/lib.rs
+++ b/lib/domain/libimagmail/src/lib.rs
@@ -44,8 +44,8 @@ extern crate toml_query;
 extern crate filters;
 #[macro_use] extern crate failure;
 extern crate resiter;
-extern crate serde;
-#[macro_use] extern crate serde_derive;
+extern crate chrono;
+extern crate notmuch as notmuch_rs;
 
 extern crate libimagerror;
 #[macro_use] extern crate libimagstore;
@@ -55,12 +55,7 @@ extern crate libimagentrylink;
 
 module_entry_path_mod!("mail");
 
-pub mod config;
-pub mod hasher;
-pub mod iter;
+pub mod notmuch;
 pub mod mail;
-pub mod mailflags;
-pub mod mid;
 pub mod store;
-pub mod util;
 
diff --git a/lib/domain/libimagmail/src/mail.rs b/lib/domain/libimagmail/src/mail.rs
index f24f5506..dd2b93db 100644
--- a/lib/domain/libimagmail/src/mail.rs
+++ b/lib/domain/libimagmail/src/mail.rs
@@ -17,371 +17,22 @@
 // Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 //
 
-use std::str::FromStr;
-
 use failure::Fallible as Result;
-use failure::ResultExt;
 use failure::Error;
-use toml_query::read::TomlValueReadExt;
-use resiter::Filter;
 
 use libimagstore::store::Entry;
-use libimagentryutil::isa::Is;
 use libimagentryutil::isa::IsKindHeaderPathProvider;
-use libimagentryref::reference::Config as RefConfig;
-use libimagentryref::reference::{Ref, RefFassade};
-use libimagentrylink::linkable::Linkable;
-use libimagstore::store::Store;
-use libimagstore::storeid::StoreId;
-use libimagstore::storeid::StoreIdIterator;
-use libimagstore::iter::get::StoreIdGetIteratorExtension;
+use libimagentryutil::isa::Is;
 
-use crate::mid::MessageId;
-use crate::mailflags::MailFlag;
-use crate::hasher::MailHasher;
-use crate::iter::MailIterator;
-use crate::iter::IntoMailIterator;
 
 provide_kindflag_path!(pub IsMail, "mail.is_mail");
 
-pub trait Mail : RefFassade + Linkable {
-    fn is_mail(&self)                                       -> Result<bool>;
-    fn get_field(&self, refconfig: &RefConfig, field: &str) -> Result<Option<String>>;
-    fn get_from(&self, refconfig: &RefConfig)               -> Result<Option<String>>;
-    fn get_to(&self, refconfig: &RefConfig)                 -> Result<Option<String>>;
-    fn get_subject(&self, refconfig: &RefConfig)            -> Result<Option<String>>;
-    fn get_message_id(&self, refconfig: &RefConfig)         -> Result<Option<MessageId>>;
-    fn get_in_reply_to(&self, refconfig: &RefConfig)        -> Result<Option<MessageId>>;
-
-    fn flags(&self, refconfig: &RefConfig) -> Result<Vec<MailFlag>>;
-    fn is_passed(&self, refconfig: &RefConfig)  -> Result<bool>;
-    fn is_replied(&self, refconfig: &RefConfig) -> Result<bool>;
-    fn is_seen(&self, refconfig: &RefConfig)    -> Result<bool>;
-    fn is_trashed(&self, refconfig: &RefConfig) -> Result<bool>;
-    fn is_draft(&self, refconfig: &RefConfig)   -> Result<bool>;
-    fn is_flagged(&self, refconfig: &RefConfig) -> Result<bool>;
-
-    fn neighbors(&self) -> Result<StoreIdIterator>;
-    fn get_neighbors<'a>(&self, store: &'a Store) -> Result<MailIterator<'a>>;
-    fn get_thread<'a>(&self, store: &'a Store) -> Result<MailIterator<'a>>;
-
+pub trait Mail {
+    fn is_mail(&self) -> Result<bool>;
 }
 
 impl Mail for Entry {
-
     fn is_mail(&self) -> Result<bool> {
-        self.is::<IsMail>()
-    }
-
-    /// Get a value of a single field of the mail file
-    fn get_field(&self, refconfig: &RefConfig, field: &str) -> Result<Option<String>> {
-        use std::fs::read_to_string;
-
-        debug!("Getting field in mail: {:?}", field);
-        let mail_file_location = self.as_ref_with_hasher::<MailHasher>().get_path(refconfig)?;
-
-        match ::mailparse::parse_mail(read_to_string(mail_file_location.as_path())?.as_bytes())
-            .context(format_err!("Cannot parse Email {}", mail_file_location.display()))?
-            .headers
-            .into_iter()
-            .filter_map(|hdr| {
-                match hdr.get_key()
-                    .context(format_err!("Cannot fetch key '{}' from Email {}", field, mail_file_location.display()))
-                    .map_err(Error::from)
-                {
-                    Ok(k) => if k == field {
-                        Some(Ok(hdr))
-                    } else {
-                        None
-                    },
-                    Err(e) => Some(Err(e)),
-                }
-            })
-            .next()
-        {
-            None          => Ok(None),
-            Some(Err(e))  => Err(e),
-            Some(Ok(hdr)) => Ok(Some(hdr.get_value()?))
-        }
-    }
-
-    /// Get a value of the `From` field of the mail file
-    ///
-    /// # Note
-    ///
-    /// Use `Mail::mail_header()` if you need to read more than one field.
-    fn get_from(&self, refconfig: &RefConfig) -> Result<Option<String>> {
-        self.get_field(refconfig, "From")
-    }
-
-    /// Get a value of the `To` field of the mail file
-    ///
-    /// # Note
-    ///
-    /// Use `Mail::mail_header()` if you need to read more than one field.
-    fn get_to(&self, refconfig: &RefConfig) -> Result<Option<String>> {
-        self.get_field(refconfig, "To")
-    }
-
-    /// Get a value of the `Subject` field of the mail file
-    ///
-    /// # Note
-    ///
-    /// Use `Mail::mail_header()` if you need to read more than one field.
-    fn get_subject(&self, refconfig: &RefConfig) -> Result<Option<String>> {
-        self.get_field(refconfig, "Subject")
-    }
-
-    /// Get a value of the `Message-ID` field of the mail file
-    ///
-    /// # Note
-    ///
-    /// Use `Mail::mail_header()` if you need to read more than one field.
-    fn get_message_id(&self, refconfig: &RefConfig) -> Result<Option<MessageId>> {
-        if let Some(s) = self.get_header().read("mail.message-id")? {
-            let s = s.as_str()
-                .ok_or_else(|| format_err!("'mail.message-id' is not a String in {}", self.get_location()))?;
-            Ok(Some(MessageId::from(String::from(s))))
-        } else {
-            self.get_field(refconfig, "Message-ID")
-                .map(|o| o.map(crate::util::strip_message_delimiters).map(MessageId::from))
-        }
-    }
-
-    /// Get a value of the `In-Reply-To` field of the mail file
-    ///
-    /// # Note
-    ///
-    /// Use `Mail::mail_header()` if you need to read more than one field.
-    fn get_in_reply_to(&self, refconfig: &RefConfig) -> Result<Option<MessageId>> {
-        self.get_field(refconfig, "In-Reply-To")
-            .map(|o| o.map(crate::util::strip_message_delimiters).map(MessageId::from))
-    }
-
-    /// Get the flags of the message
-    fn flags(&self, refconfig: &RefConfig) -> Result<Vec<MailFlag>> {
-        let path = self.as_ref_with_hasher::<MailHasher>().get_path(refconfig)?;
-
-        if !path.exists() {
-            return Err(format_err!("Path {} does not exist", path.display()))
-        }
-
-        {
-            // Now parse mail flags
-            path.to_str()
-                .ok_or_else(|| format_err!("Path is not UTF-8: {}", path.display()))?
-                .split("2,")
-                .map(String::from)
-                .collect::<Vec<String>>()
-                .split_last()
-                .ok_or_else(|| format_err!("Splitting path into prefix and flags failed: {}", path.display()))?
-                .0
-                .chars()
-                .map(|c| c.to_string())
-                .map(|c| MailFlag::from_str(&c))
-                .collect::<Result<Vec<_>>>()
-        }
-    }
-
-    /// Check whether the mail is passed
-    fn is_passed(&self, refconfig: &RefConfig)  -> Result<bool> {
-        self.flags(refconfig).map(|fs| fs.into_iter().any(|f| MailFlag::Passed == f))
-    }
-
-    /// Check whether the mail is replied
-    fn is_replied(&self, refconfig: &RefConfig) -> Result<bool> {
-        self.flags(refconfig).map(|fs| fs.into_iter().any(|f| MailFlag::Replied == f))
-    }
-
-    /// Check whether the mail is seen
-    fn is_seen(&self, refconfig: &RefConfig)    -> Result<bool> {
-        self.flags(refconfig).map(|fs| fs.into_iter().any(|f| MailFlag::Seen == f))
-    }
-
-    /// Check whether the mail is trashed
-    fn is_trashed(&self, refconfig: &RefConfig) -> Result<bool> {
-        self.flags(refconfig).map(|fs| fs.into_iter().any(|f| MailFlag::Trashed == f))
-    }
-
-    /// Check whether the mail is draft
-    fn is_draft(&self, refconfig: &RefConfig)   -> Result<bool> {
-        self.flags(refconfig).map(|fs| fs.into_iter().any(|f| MailFlag::Draft == f))
-    }
-
-    /// Check whether the mail is flagged
-    fn is_flagged(&self, refconfig: &RefConfig) -> Result<bool> {
-        self.flags(refconfig).map(|fs| fs.into_iter().any(|f| MailFlag::Flagged == f))
-    }
-
-    /// Get all direct neighbors for the Mail
-    ///
-    /// # Note
-    ///
-    /// This fetches only the neighbors which are linked. So it basically only checks the entries
-    /// which this entry is linked to and filters them for Mail::is_mail()
-    ///
-    /// # Warning
-    ///
-    /// Might yield store entries which are not a Mail in the Mail::is_mail() sence but are simply
-    /// stored in /mail in the store.
-    ///
-    /// To be sure, you should filter this iterator after getting the FileLockEntries from Store.
-    /// Or use `Mail::get_neighbors(&store)`.
-    ///
-    fn neighbors(&self) -> Result<StoreIdIterator> {
-        let iter = self
-            .links()?
-            .map(|link| link.into())
-            .filter(|id: &StoreId| id.is_in_collection(&["mail"]))
-            .map(Ok);
-
-        Ok(StoreIdIterator::new(Box::new(iter)))
-    }
-
-    /// Get alldirect neighbors for the Mail (as FileLockEntry)
-    ///
-    /// # See also
-    ///
-    /// Documentation of `Mail::neighbors()`.
-    fn get_neighbors<'a>(&self, store: &'a Store) -> Result<MailIterator<'a>> {
-        self.links()
-            .map(|iter| {
-                iter.map(|link| link.into())
-                    .map(Ok)
-                    .into_get_iter(store)
-                    .into_mail_iterator()
-            })
-    }
-
-    /// Get the full thread starting from this Mail
-    ///
-    /// This function recursively traverses the linked mails, assumes them all to be in the same
-    /// thread and returns an iterator over all Mails it finds in this way.
-    ///
-    /// # Warning
-    ///
-    /// If a Mail is linked to this mail (even transitively!) but is _not_ in the same thread, it
-    /// is considered to be in the same thread.
-    ///
-    /// This function works recursively. Keep that in mind for large threads. Because it needs to
-    /// collect() internally, it might take a lot of memory for large threads.
-    ///
-    /// # Return value
-    ///
-    /// This function returns an Iterator over StoreIds in the same thread as this mail itself.
-    /// It does not yield any qualification about the distance between a mail in this thread and
-    /// this very mail.
-    ///
-    fn get_thread<'a>(&self, store: &'a Store) -> Result<MailIterator<'a>> {
-        trace!("Getting thread, starting point at: {}", self.get_location());
-        let mut thread = vec![self.get_location().clone()];
-
-        fn traverse<'a>(entry: &'a Entry, thread: &mut Vec<StoreId>, store: &Store) -> Result<()> {
-            // Helper function to get neighbors of a Mail, but filtered
-            fn get_filtered_neighbors<'a>(entry: &'a Entry, skiplist: &[StoreId]) -> Result<Vec<StoreId>> {
-                trace!("Getting filtered neighbors of {}", entry.get_location());
-                entry.neighbors()?.filter_ok(|id| !skiplist.contains(id)).collect()
-            }
-
-            // Get the neighbors, filtered by StoreIds which are already in the thread
-            // Then iterate over them
-            for n in get_filtered_neighbors(entry, thread)? {
-                trace!("Fetching {}", n);
-
-                // Get the FileLockEntry for the StoreId, or fail if it cannot be found
-                let next_entry = store.get(n.clone())?.ok_or_else(|| format_err!("Cannot find {}", n))?;
-
-                // if the FileLockEntry is a Mail
-                if next_entry.is_mail()? {
-                    trace!("{} is a Mail", n);
-                    thread.push(n); // it belongs to the thread
-
-                    // And then traverse further starting from the current Mail
-                    traverse(&next_entry, thread, store)?;
-                }
-            }
-
-            Ok(())
-        }
-
-        trace!("Starting traversing...");
-        traverse(self, &mut thread, store)?;
-        trace!("Finished traversing.");
-        trace!("Found {} entries in thread", thread.len());
-
-        let iter = StoreIdIterator::new(Box::new(thread.into_iter().map(Ok)))
-            .into_get_iter(store)
-            .into_mail_iterator();
-
-        Ok(iter)
-    }
-
-}
-
-#[derive(Debug)]
-pub struct MailHeader<'a>(Vec<::mailparse::MailHeader<'a>>);
-
-impl<'a> From<Vec<::mailparse::MailHeader<'a>>> for MailHeader<'a> {
-    fn from(mh: Vec<::mailparse::MailHeader<'a>>) -> Self {
-        MailHeader(mh)
-    }
-}
-
-impl<'a> MailHeader<'a> {
-    /// Get a value of a single field of the mail file
-    pub fn get_field(&self, field: &str) -> Result<Option<String>> {
-        match self.0
-            .iter()
-            .filter_map(|hdr| {
-                match hdr.get_key()
-                    .context(format_err!("Cannot get field {}", field))
-                    .map_err(Error::from)
-                {
-                    Ok(key) => if key == field {
-                        Some(Ok(hdr))
-                    } else {
-                        None
-                    },
-                    Err(e) => Some(Err(e))
-                }
-            })
-            .next()
-        {
-            None          => Ok(None),
-            Some(Err(e))  => Err(e),
-            Some(Ok(hdr)) => Ok(Some(hdr.get_value()?))
-        }
-    }
-
-    /// Get a value of the `From` field of the mail file
-    pub fn get_from(&self) -> Result<Option<String>> {
-        self.get_field("From")
+        self.is::<IsMail>().map_err(Error::from)
     }
-
-    /// Get a value of the `To` field of the mail file
-    pub fn get_to(&self) -> Result<Option<String>> {
-        self.get_field("To")
-    }
-
-    /// Get a value of the `Subject` field of the mail file
-    pub fn get_subject(&self) -> Result<Option<String>> {
-        self.get_field("Subject")
-    }
-
-    /// Get a value of the `Message-ID` field of the mail file
-    pub fn get_message_id(&self) -> Result<Option<String>> {
-        self.get_field("Message-ID")
-    }
-
-    /// Get a value of the `In-Reply-To` field of the mail file
-    pub fn get_in_reply_to(&self) -> Result<Option<MessageId>> {
-        self.get_field("In-Reply-To")
-            .map(|o| o.map(crate::util::strip_message_delimiters).map(MessageId::from))
-    }
-
-    // TODO: Offer functionality to load and parse mail _once_ from disk, and then use helper object
-    // to offer access to header fields and content.
-    //
-    // With the existing functionality, one has to open-parse-close the file all the time, which is
-    // _NOT_ optimal.
 }
diff --git a/lib/domain/libimagmail/src/mailflags.rs b/lib/domain/libimagmail/src/mailflags.rs
deleted file mode 100644
index 5fd52761..00000000
--- a/lib/domain/libimagmail/src/mailflags.rs
+++ /dev/null
@@ -1,93 +0,0 @@
-//
-// imag - the personal information management suite for the commandline
-// Copyright (C) 2015-2020 Matthias Beyer <mail@beyermatthias.de> and contributors
-//
-// This library is free software; you can redistribute it and/or
-// modify it under the terms of the GNU Lesser General Public
-// License as published by the Free Software Foundation; version
-// 2.1 of the License.
-//
-// This library is distributed in the hope that it will be useful,
-// but WITHOUT ANY WARRANTY; without even the implied warranty of
-// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-// Lesser General Public License for more details.
-//
-// You should have received a copy of the GNU Lesser General Public
-// License along with this library; if not, write to the Free Software
-// Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
-//
-
-use std::fmt::{Display, Result as FmtResult, Formatter};
-use std::str::FromStr;
-
-use failure::Fallible as Result;
-use failure::Error;
-
-/// Message flags
-///
-/// As defined by https://cr.yp.to/proto/maildir.html with strong typing
-#[derive(Copy, Clone, Debug, Eq, PartialEq)]
-pub enum MailFlag {
-    /// Flag "P" (passed): the user has resent/forwarded/bounced this message to someone else.
-    Passed,
-
-    /// Flag "R" (replied): the user has replied to this message.
-    Replied,
-
-    /// Flag "S" (seen): the user has viewed this message, though perhaps he didn't read all the way through it.
-    Seen,
-
-    /// Flag "T" (trashed): the user has moved this message to the trash; the trash will be emptied by a later user action.
-    Trashed,
-
-    /// Flag "D" (draft): the user considers this message a draft; toggled at user discretion.
-    Draft,
-
-    /// Flag "F" (flagged): user-defined flag; toggled at user discretion.
-    Flagged,
-}
-
-impl MailFlag {
-    pub fn as_char(self) -> char {
-        match self {
-            MailFlag::Passed  => 'P',
-            MailFlag::Replied => 'R',
-            MailFlag::Seen    => 'S',
-            MailFlag::Trashed => 'T',
-            MailFlag::Draft   => 'D',
-            MailFlag::Flagged =&