SMTP ERROR: Username command failed: 535 5.7.8

[Geo_Link]

I'm trying to configure helpdesk but getting an error when trying to enable TLS. Also, when TLS is disabled no matter what i type in creds it always says "Successful connection". There is an error I keep getting:

Code: Select all

SERVER -> CLIENT: 220 my.server.net ESMTP Postfix (Ubuntu)
CLIENT -> SERVER: EHLO hesk
SERVER -> CLIENT: 250-mail.bntu.by
                   	                  250-PIPELINING
                   	                  250-SIZE 314572800
                   	                  250-ETRN
                   	                  250-STARTTLS
                   	                  250-ENHANCEDSTATUSCODES
                   	                  250-8BITMIME
                   	                  250 DSN
CLIENT -> SERVER: STARTTLS
SERVER -> CLIENT: 220 2.0.0 Ready to start TLS
CLIENT -> SERVER: EHLO hesk
SERVER -> CLIENT: 250-mail.bntu.by
                   	                  250-PIPELINING
                   	                  250-SIZE 314572800
                   	                  250-ETRN
                   	                  250-AUTH PLAIN LOGIN CRAM-MD5
                   	                  250-AUTH=PLAIN LOGIN CRAM-MD5
                   	                  250-ENHANCEDSTATUSCODES
                   	                  250-8BITMIME
                   	                  250 DSN
CLIENT -> SERVER: AUTH CRAM-MD5
SERVER -> CLIENT: 334 PDYzOTcyMTU0NjbruhUwNjIuMTY2MDcyNzEyNUBtYWlsLmJudHUuYnk+
CLIENT -> SERVER: [credentials hidden]
SERVER -> CLIENT: 535 5.7.8 Error: authentication failed: PDYzOTcyMTU0NjbruhNjIuMTY2MDcyNzEyNUBtYWlsLmJudHUuYnk+
SMTP ERROR: Username command failed: 535 5.7.8 Error: authentication failed: PDYzOTcyMTU0NjUyNjUwNjIuMTY2MDcyNzEyNbruhnk+

[Klemen]

535 5.7.8 means the server is rejecting the username and password.

Are you using a third party email provider such as Gmail? Perhaps your provider requires an "App password" and doesn't allow using the account password (Gmail does that for example)?

[Geo_Link]

No, I'm using our corporative mail server that requires, well, login and password. I checked, they are 100% correct, but the error is still here.

[Klemen]

You may want to talk to your corporate mailserver administrator because the username/password is failing. The connection itself is OK.

Maybe the user doesn't have SMTP access enabled or something? Mail server logs should tell you more.