diff --git a/src/app/Backends/IMAP.php b/src/app/Backends/IMAP.php
--- a/src/app/Backends/IMAP.php
+++ b/src/app/Backends/IMAP.php
@@ -733,7 +733,7 @@
             $config['user'] = $login_as;
         }
 
-        $imap->connect($config['host'], $config['user'], $config['password'], $config['options']);
+        $imap->connect($config['host'], $login_as, $config['password'], $config['options']);
 
         if (!$imap->connected()) {
             $message = sprintf("Login failed for %s against %s. %s", $config['user'], $config['host'], $imap->error);