Our email client will no longer send email via a relay service that has worked fine for the past 5 years or more.
We had some issues with our email provider in that they changed the mx records for our domain before being asked to do so, i.e. before the alternative was fully setup and configured, so for a brief time the domain would not allow receiving or sending of mail even though the outgoing has always used a relay service, so I don't understand why this would be so.
They've now been reset and mail is now coming in again but we can't send. I've created an alternative smtp relay service but we still get the same error message email-send-error.png
From the error message, the SMTP connection was made but the remote server refused to accept the message because he didn't know the recipient's email address.
I'd check that with the recipient - maybe there's some subtle typo, or that guy no longer works there and his mail accound got disabled (bad idea if customers mails are not redirected to another account).
After correcting the authorisation to CRAM MD5 one error was resolved and another appeared, see latest message.
Strangely this works in Outlook but not in Goldmine. I messed around with the settings and found that when I changed the reply to address to something other than the domain to which this refers, i.e. to a personal Gmail address it works fine in Goldmine too.
I'd check that with the recipient - maybe there's some subtle typo, or that guy no longer works there and his mail accound got disabled (bad idea if customers mails are not redirected to another account).