feat: Always move outgoing auto-generated messages to the mvbox

Recently there are many questions on the Delta Chat forum why some unexpected encrypted messages
appear in Inbox. Seems they are mainly sync messages, though that also obviously happens to
SecureJoin messages. Anyway, regardless of the `MvboxMove` setting, auto-generated outgoing messages
should be moved to the DeltaChat folder so as not to complicate co-using Delta Chat with other MUAs.

src/config.rs

@@ -13,7 +13,7 @@ use strum_macros::{AsRefStr, Display, EnumIter, EnumString};
 use tokio::fs;
 
 use crate::blob::BlobObject;
-use crate::constants::{self, DC_VERSION_STR};
+use crate::constants;
 use crate::context::Context;
 use crate::events::EventType;
 use crate::log::LogExt;
@@ -131,7 +131,8 @@ pub enum Config {
     #[strum(props(default = "0"))]
     SentboxWatch,
 
-    /// True if chat messages should be moved to a separate folder.
+    /// True if chat messages should be moved to a separate folder. Auto-sent messages like sync
+    /// ones are moved there anyway.
     #[strum(props(default = "1"))]
     MvboxMove,
 
@@ -385,9 +386,6 @@ impl Config {
     /// multiple users are sharing an account. Another example is `Self::SyncMsgs` itself which
     /// mustn't be controlled by other devices.
     pub(crate) fn is_synced(&self) -> bool {
-        // NB: We don't restart IO from the synchronisation code, so `MvboxMove` isn't effective
-        // immediately if `ConfiguredMvboxFolder` is unset, but only after a reconnect (see
-        // `Imap::prepare()`).
         matches!(
             self,
             Self::Displayname
@@ -401,10 +399,7 @@ impl Config {
 
     /// Whether the config option needs an IO scheduler restart to take effect.
     pub(crate) fn needs_io_restart(&self) -> bool {
-        matches!(
-            self,
-            Config::MvboxMove | Config::OnlyFetchMvbox | Config::SentboxWatch
-        )
+        matches!(self, Config::OnlyFetchMvbox | Config::SentboxWatch)
     }
 }
 
@@ -430,7 +425,7 @@ impl Context {
                         .into_owned()
                 })
             }
-            Config::SysVersion => Some((*DC_VERSION_STR).clone()),
+            Config::SysVersion => Some((*constants::DC_VERSION_STR).clone()),
             Config::SysMsgsizeMaxRecommended => Some(format!("{RECOMMENDED_FILE_SIZE}")),
             Config::SysConfigKeys => Some(get_config_keys_string()),
             _ => self.sql.get_raw_config(key.as_ref()).await?,
@@ -488,7 +483,8 @@ impl Context {
     /// Returns true if movebox ("DeltaChat" folder) should be watched.
     pub(crate) async fn should_watch_mvbox(&self) -> Result<bool> {
         Ok(self.get_config_bool(Config::MvboxMove).await?
-            || self.get_config_bool(Config::OnlyFetchMvbox).await?)
+            || self.get_config_bool(Config::OnlyFetchMvbox).await?
+            || !self.get_config_bool(Config::IsChatmail).await?)
     }
 
     /// Returns true if sentbox ("Sent" folder) should be watched.

src/configure.rs

@@ -477,8 +477,7 @@ async fn configure(ctx: &Context, param: &mut LoginParam) -> Result<()> {
         ctx.set_config(Config::E2eeEnabled, Some("1")).await?;
     }
 
-    let create_mvbox = ctx.should_watch_mvbox().await?;
-
+    let create_mvbox = !is_chatmail;
     imap.configure_folders(ctx, &mut imap_session, create_mvbox)
         .await?;
 

src/constants.rs

@@ -209,7 +209,7 @@ pub const WORSE_IMAGE_SIZE: u32 = 640;
 // Key for the folder configuration version (see below).
 pub(crate) const DC_FOLDERS_CONFIGURED_KEY: &str = "folders_configured";
 // this value can be increased if the folder configuration is changed and must be redone on next program start
-pub(crate) const DC_FOLDERS_CONFIGURED_VERSION: i32 = 4;
+pub(crate) const DC_FOLDERS_CONFIGURED_VERSION: i32 = 5;
 
 // If more recipients are needed in SMTP's `RCPT TO:` header, the recipient list is split into
 // chunks. This does not affect MIME's `To:` header. Can be overwritten by setting

src/headerdef.rs

@@ -11,6 +11,7 @@ pub enum HeaderDef {
     Date,
     From_,
     To,
+    AutoSubmitted,
 
     /// Carbon copy.
     Cc,

src/imap.rs

@@ -446,7 +446,11 @@ impl Imap {
             .get_raw_config_int(constants::DC_FOLDERS_CONFIGURED_KEY)
             .await?;
         if folders_configured.unwrap_or_default() < constants::DC_FOLDERS_CONFIGURED_VERSION {
-            let create_mvbox = true;
+            let is_chatmail = match context.get_config_bool(Config::FixIsChatmail).await? {
+                false => session.is_chatmail(),
+                true => context.get_config_bool(Config::IsChatmail).await?,
+            };
+            let create_mvbox = !is_chatmail || context.get_config_bool(Config::MvboxMove).await?;
             self.configure_folders(context, &mut session, create_mvbox)
                 .await?;
         }
@@ -1811,6 +1815,20 @@ async fn needs_move_to_mvbox(
     context: &Context,
     headers: &[mailparse::MailHeader<'_>],
 ) -> Result<bool> {
+    let has_chat_version = headers.get_header_value(HeaderDef::ChatVersion).is_some();
+    if !context.get_config_bool(Config::IsChatmail).await?
+        && has_chat_version
+        && headers
+            .get_header_value(HeaderDef::AutoSubmitted)
+            .filter(|val| val.to_ascii_lowercase() == "auto-generated")
+            .is_some()
+    {
+        if let Some(from) = mimeparser::get_from(headers) {
+            if context.is_self_addr(&from.addr).await? {
+                return Ok(true);
+            }
+        }
+    }
     if !context.get_config_bool(Config::MvboxMove).await? {
         return Ok(false);
     }
@@ -1824,7 +1842,7 @@ async fn needs_move_to_mvbox(
         return Ok(false);
     }
 
-    if headers.get_header_value(HeaderDef::ChatVersion).is_some() {
+    if has_chat_version {
         Ok(true)
     } else if let Some(parent) = get_prefetch_parent_message(context, headers).await? {
         match parent.is_dc_message {

src/imap/session.rs

@@ -24,6 +24,7 @@ const PREFETCH_FLAGS: &str = "(UID INTERNALDATE RFC822.SIZE BODY.PEEK[HEADER.FIE
                               FROM \
                               IN-REPLY-TO REFERENCES \
                               CHAT-VERSION \
+                              AUTO-SUBMITTED \
                               AUTOCRYPT-SETUP-MESSAGE\
                               )])";