Our TeamCity server suddenly stopped being able to send e-mail notifications as of late last week. It had been working normally for several months prior to that. No configuration changes were made in TeamCity or to our Exchange server that should have precipitated this issue.
It gives this error message: Failed to send email notification via SMTP server: No authentication mechansims supported by both server and client
Does anyone have any suggestions on how to resolve this? We've tested and we're definitely able to send mail from this server, it just seems TeamCity is having problems authenticating for whatever reason.
Our Exchange server does not use SSL and setting it to do so is not an option as it would affect more than just TeamCity.
Thanks for any help.