I am currently using version 2.2.6
Since we first installed the server, we have been unable to send email using our SMTP server when outside the local LAN (outside the office).
The error we receive in MS Outlook is 0x80042109.
I've tried using IP address and hostname in email account settings, to no avail.
Port 25 is open on my firewall (and redirecting correctly to the mail server) and my ISP does not block traffic on port 25.
My server does not appear on any blacklists
I've searched through the forums and found a handful of users who had similar problems, but no firm solutions:
Any help would be greatly appreciated.