+ - Fixed checking for quota when appending to Sent folder (#1172694).
+ - Create a generic function to empty a folder tree, thanks to
+ Randy Smith (#1145578).
+ - Add robots noindex/nofollow meta tag to SquirrelMail generated pages.
+ - Fix incorrect folder hierarchy display (#1009654), thanks
+ Awais Ahmad for the patch (#1082558).
+ - src/delete_message.php script is disabled. It provided functions that
+ could be implemented without playing with multiple redirects.
+ - Remove lots of obsoleted code from left_main.php.
+ - Partial support of IMAP REFERRAL: do not fail on IMAP REFERRAL response
+ (RFC 2221) but log the user out with a hint. Patch by Ariel Arjona
+ (#1006242).
+ - Fixed SquirrelMail language cookie detection in php register_globals=off.
+ - If default SquirrelMail language is set to empty string, interface will
+ try to follow browser's HTTP_ACCEPT_LANGUAGE header or fallback to en_US
+ (#764709).
+ - If From: field is unset in an email, header object for from field is not
+ correctly set, and generates an error on reply (#1179754).
+ - Add Cancel button to addressbook (#1180565).
+ - RFC 2046: Send mixed messages with multipart/alternative nested boundaries
+ with correct boundary strings.
+ - WARNING: if same user data storage location is used to store SquirrelMail
+ 1.4.x and 1.5.1+ user settings, SquirrelMail 1.5.1+ will reset mailbox
+ display order (Options->Index Options) in stable. Backup your data before
+ testing 1.5.1+ or use different storage location.