Mac Mail error codes

If a customer is getting the following dialogue when try to send a mail where it cant verify smtp mail server:

Try: To click on connect button to see if will allow connection to server and send mail.

If not change the smtp port from 25 to 587.

If you get the same message as above and the cert is '*.novara.ie' ticke the box Always trust '*.novara.ie' when connecting to mail.yourdomain.com

Reason: The is ad-hoc novara certificate to allow encryption

o Apple Mail: If more than one smtp server is configured, if the first one fails, it will offer a list of the others to choose from.

If one server:

The outgoing mail server failed to deliver this message. The connection to the server "<SMTPSERVER>" on port 25 timed out.

o Microsoft Entourage:

After about 1 minute:

Error Description Error: Mail could not be sent using the account <accountname> A connection failure has occurred Error: -23016

Solution: change the smtp port from 25 to 587 OR replace current mail server with your ISP mail server