We recently updated our smartermail server from version16.3.6508 (Oct 26, 2017) to version 16.3.6572 (Dec 29, 2017).
Since then, some users are not able to send mail via SMTP anymore. Authentication via POP and IMAP works just fine but when sending mail, a SMTP error 535 authentication failed is logged.
It seems that it is related to the presence of accented characters (like é) in the user password. We made some tests with several connection parameters to the smtp server, and all are rejected.
I used WireShark to analyse the SMTP traffic of an unencrypted connection dialog and the base 64 encoded password is transmitted correctly, though it is rejected. Changing the user password to a non accented password fix the bug, so it doesn't seem to be user account related.
Does anyone else have encountered similar issues? Or is it a bug of this release?
Note: we have updated to last version 16.3.6579 (Jan 5, 2018) but this doesn't clear the issue.
Thanks for your support.
Arts et Vie