Error sending email

As of yesterday (more or less, this is a secondary account so I don’t really know when the trouble started), I can check and get the mail OK, but I cannot send.

Checking the logs, there’s this error message:
SMTP: 16:38:25 [rx] 250-ETRN
SMTP: 16:38:25 [rx] 250-AUTH LOGIN PLAIN CRAM-MD5
SMTP: 16:38:25 [rx] 250-AUTH=LOGIN PLAIN CRAM-MD5
SMTP: 16:38:25 [rx] 250-XVERP
SMTP: 16:38:25 [rx] 250 8BITMIME
SMTP: 16:38:25 [tx] AUTH CRAM-MD5
SMTP: 16:38:25 [rx] 334 PDMxOTM2MDEzNjEuNTMxMzY5OUBiYXJhY3VzLmRyZWFtaG9zdC5jb20+
SMTP: 16:38:25 [tx] bTYwMDE0NzQgZmVkODU5MDRiMzM3YTk1MTU2N2ViZjcyMmJhNmIxNGU=
SMTP: 16:38:31 [rx] 535 Error: authentication failed

However, this account was working well till the last few days and I’ve not changed the settings. User name and password are correct.

Anybody else has found this problem? Any idea will be appreciated.

I have not yet checked my logs to see if the error is the same, but a client expirenced the same issue Friday.

I’m still able to send outgoign E-mail from my account on the same server so not sure where the problem might lie, or if for me it was a temporary issue.


this is the log from my email client, mind you. It seems that now the mail server is at, and I think this is new, but I don’t know if it’s relevant. I’m going to send a support ticket and see what they have to say. I’ll post here the answer when I get it.

My guess is that this is a configuration error on It claims to support CRAM-MD5 authentication and therefore the client uses it. But the other servers (at least for my domain) do not advertise CRAM-MD5, so I think that’s a mistake.

If your domain is like mine, then there are several IPs associated with, and it might be just chance which one the mail client uses. You could configure your mail client with one of the other servers.

You’re probably right. Today I can send email normally. According to the logs, the server is now, and does not claim CRAM-MD5 authentication, just PLAIN.
Anyway, the mail is working again.