Add extra_identities configuration flag

Closes #119

Multi identies per account #119 https://git.meli.delivery/meli/meli/issues/119

docs/meli.conf.5

@@ -138,6 +138,9 @@ The glob wildcard
 can be used to match every mailbox name and path.
 .It Ic identity Ar String
 Your e-mail address that is inserted in the From: headers of outgoing mail.
+.It Ic extra_identities Ar [String,]
+Extra e-mail address identities.
+When replying to an e-mail addressed to one of these identities, the From: header will be adjusted to its value instead of the default identity.
 .El
 .TS
 allbox tab(:);

melib/src/conf.rs

@@ -30,6 +30,7 @@ pub struct AccountSettings {
     pub root_mailbox: String,
     pub format: String,
     pub identity: String,
+    pub extra_identities: Vec<String>,
     pub read_only: bool,
     pub display_name: Option<String>,
     pub subscribed_mailboxes: Vec<String>,

src/components/mail/compose.rs

@@ -249,6 +249,21 @@ impl Composer {
         ret.draft
             .set_header("In-Reply-To", envelope.message_id_display().into());
 
+        if let Some(reply_to) = envelope
+            .other_headers()
+            .get("To")
+            .and_then(|v| v.as_str().try_into().ok())
+        {
+            let to: &str = reply_to;
+            let extra_identities = &account.settings.account.extra_identities;
+            if let Some(extra) = extra_identities
+                .iter()
+                .find(|extra| to.contains(extra.as_str()))
+            {
+                ret.draft.set_header("From", extra.into());
+            }
+        }
+
         // "Mail-Followup-To/(To+Cc+(Mail-Reply-To/Reply-To/From)) for follow-up,
         // Mail-Reply-To/Reply-To/From for reply-to-author."
         // source: https://cr.yp.to/proto/replyto.html

src/conf.rs

@@ -155,6 +155,8 @@ pub struct FileAccount {
     root_mailbox: String,
     format: String,
     identity: String,
+    #[serde(default)]
+    extra_identities: Vec<String>,
     #[serde(default = "none")]
     display_name: Option<String>,
 
@@ -254,6 +256,7 @@ impl From<FileAccount> for AccountConf {
             root_mailbox,
             format,
             identity,
+            extra_identities: x.extra_identities.clone(),
             read_only: x.read_only,
             display_name,
             subscribed_mailboxes: x.subscribed_mailboxes.clone(),
@@ -444,6 +447,7 @@ This is required so that you don't accidentally start meli and find out later th
                 root_mailbox,
                 format,
                 identity,
+                extra_identities,
                 read_only,
                 display_name,
                 subscribed_mailboxes,
@@ -461,6 +465,7 @@ This is required so that you don't accidentally start meli and find out later th
                 root_mailbox,
                 format: format.clone(),
                 identity,
+                extra_identities,
                 read_only,
                 display_name,
                 subscribed_mailboxes,