Configuring Mail in OS X for Use With Shaw

Recently, Mail stopped sending through my outgoing mail sever on my MacBook. In the office, we have SHAW and send through shawmail.wp.shawcable.net as our outbound mail servers. Shaw has a tool if you need to find your local mail server and they also have a complete step-by-step walkthrough there as well. However, this one issue is not documented there as of this writing.

Apparently during a recent upgrade, Shaw's mail servers no longer allow the default setup in Mail.app to work. The default setup polls the mail server on potential mail ports at 25, 465, 587 until it finds the correct one, then uses that port to send through. This now fails. 

In order to fix this, you need to choose the second option and specify that you want to use port 25 exclusively. That should do it.

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