How to change the outgoing mail port in 10.5

Select the Preferences from the Mail menu.

Select Accounts

Be sure to choose thenon-working Mail account

Click the drop down box next to the Outgoing Mail Server (SMTP)

Choose Edit Server List…

Click Advanced

Then click Use default ports. NOTE – if you are running a different version of OS X, your screen mail look a bit different from this picture. The important aspect of it is to make sure the settings, no matter the version, are the same.

So, if your Use Default Ports selection doesn’t show 25, 465, 587, the custom port to either 465 or 587 (25 will not work, don’t even try it). Some versions of OS X will allow 465, some won’t, and it’s a good guess as to which one will work, so if one doesn’t work, try the other one.

See below for how to test.

Testing to see if it works…

Choose Connection Doctor from the Window menu

Connection Doctor

You will see a screen similar to this appear. If you have green lights next to the outgoing mail server (or all green lights) you are good to go!