2 files changed, 11 insertions, 0 deletions
diff --git a/program/lib/Roundcube/rcube_storage.php b/program/lib/Roundcube/rcube_storage.php
index 245d911c0..7ec05b7af 100644
--- a/program/lib/Roundcube/rcube_storage.php
+++ b/program/lib/Roundcube/rcube_storage.php
@@ -65,6 +65,7 @@ abstract class rcube_storage
         'MAIL-REPLY-TO',
         'RETURN-PATH',
         'DELIVERED-TO',
+        'ENVELOPE-TO',
     );
 
     const UNKNOWN       = 0;
diff --git a/program/steps/mail/compose.inc b/program/steps/mail/compose.inc
index d181a72e6..d764f5289 100644
--- a/program/steps/mail/compose.inc
+++ b/program/steps/mail/compose.inc
@@ -455,6 +455,16 @@ function rcmail_identity_select($MESSAGE, $identities, $compose_mode)
     }
   }
 
+  // Fallback using Envelope-To
+  if ($from_idx === null && ($envelope_to = $MESSAGE->headers->others['envelope-to'])) {
+    foreach ($identities as $idx => $ident) {
+      if (in_array($ident['email_ascii'], (array)$envelope_to)) {
+        $from_idx = $idx;
+        break;
+      }
+    }
+  }
+
   return $identities[$from_idx !== null ? $from_idx : $default_identity];
 }