Mandrill SMTP Configuration Issue

[dloewen]

Hi, I'm using Mandrill's SMTP sending method, which works OK but periodically (sometimes 1 day, sometimes 5 days) stops working. At that point if I go into the CSF configuration and simply click "Change" without changing anything, after it reloads CSF and LFD the mail sends again.

The error message that shows when it stops working is "smtp error: could not authenticate."

The SMTP is set to send with port 587 and TLS encryption.
I allowed the sending port with TCP_OUT (587).

I also whitelisted Mandrill's sending IPs (though that shouldn't matter since the server doesn't interact with these AFAIK)
205.201.128.0/20
198.2.128.0/18

Any ideas why it would stop working until the configuration is reloaded? I can't make sense of why it would stop once and a while.

[Sergio]

If the error shows:
"smtp error: could not authenticate."

there is a problem with the smtp password and CSF is doing its work, block any IP that doesn't has the right authentication.