Many of our client here in Qatar having issues sending mail to some organization like QP , Qatar Petrolium through Barracuda. Please see the resolution here.
Firmware Version 6.X
‘This is issue has been addressed on that
- Fix: Resolved issue with connecting to recipient servers when Enable SMTP over TLS/SSL is enabled (see the ADVANCED > Email Protocol page).
Advanced > Email Protocol and at the bottom change “Enable SMTP over TLS/SSL” to NO.