We've been using outlook email addresses to send outgoing emails over SMTP for a few years now without issue, however recently some of our agents noticed they seemed to be not receiving some emails seemingly randomly. After looking at the system logs we found a large number of "Mailer Error" errors. These errors seem to occur in pairs, the first error in the pair has the message "Unable to email via SMTP:smtp.office365.com:587 [email address] Failed to set sender: email address [SMTP: Failed to write to socket: unknown error (code: -1, response: )]" and then the second error in the pair says "Unable to email via php mail function:"user" mail() returned failure"

We haven't recently made any changes to the OSTicket set up and as I mentioned before these errors are seemingly random. Any advice to help resolve this would be greatly appreciated.

1.10 is out of support and very end of life.
My first suggestion is upgrade to a contemporary version.

Thanks for the advice. I'm going to start looking into how to get updated. Later yesterday we were able to discover a new error that was being thrown when we go to change settings on one of the email addresses. This error mentioned "authentication failure [SMTP: Invalid response code received from server (code: 421, response: 4.7.66 TLS 1.0 and 1.1 are not supported. Please upgrade/update your client to support TLS 1.2" Do you know if this is something that would be resolved through updating to a newer software? or would there be further action needed as well?

It sounds like the mail host discontinued support for TLS 1 and 1.1.
(I seem to recall reading something about that a while back.)
osTicket 1.10 is really old I do not recall if it worked with tls 1.2.
I can tell you though that I am running 1.15.4 and we use m365 for mail.

My company recently having the same issue, the problem is due to the o365 mfa not compatible with the osticket old version( mine is version 1.9). The problem was solved after upgrade it to latest version - v1.15.

Write a Reply...