diff --git a/CHANGELOG b/CHANGELOG
index 2d1e02016..74fa86039 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -1,6 +1,7 @@
 CHANGELOG RoundCube Webmail
 ===========================
 
+- Fix long e-mail addresses validation (#1486453)
 - Remember search modifiers in user prefs (#1486146)
 - Added force_7bit option to force MIME encoding of plain/text messages (#1486510)
 - Use case sensitive check when checking for default folders (#1486346)
diff --git a/program/include/main.inc b/program/include/main.inc
index 9cf6dd00c..da588b240 100644
--- a/program/include/main.inc
+++ b/program/include/main.inc
@@ -1511,8 +1511,12 @@ function check_email($email)
   if (preg_match('/[\x00-\x1F\x7F-\xFF]/', $email))
     return false;
 
-  // Check that there's one @ symbol, and that the lengths are right
-  if (!preg_match('/^([^@]{1,64})@([^@]{1,255})$/', $email, $email_array))
+  // Check for length limit specified by RFC 5321 (#1486453)
+  if (strlen($email) > 254) 
+    return false;
+
+  // Check that there's one @ symbol
+  if (!preg_match('/^([^@]+)@([^@]+)$/', $email, $email_array))
     return false;
 
   // Check local part