I ran the service pack update and it has killed our SMTP. Has anybody else had this issue? We can't send/ recieve "Welcome emails", Webmeeting invites and the email test fails "This operation was canceled".
I am running on Linux SP3 (latest). I just ran the test and it worked OK from here.
I tested on a client system on Windows SP4 and that works fine also.
Not much help to you I know, but at least you know it is not normal.
When 3CX PhoneSystem needs to deliver email notifications, the SMTP mechanisms allowed can either be unauthenticated or authenticated using clear text. According to the error something stop the communication with SMTP. Please check your server may be configured to allow only TLS or SSL exchange or you can troubleshoot that with wireshark.