throwable

After setting up an e-mail account on a new Mac, I ran into a curious problem. Incoming mail worked fine, but outgoing mail refused to go. Often this is a sign that the ISP is blocking port 25 (see Mail 3.0 Help: If the connection to the server on port 25 times out), but this time that wasn’t the case.

The first sign that something wasn’t right appeared during the account setup process when I entered the information on the outgoing mail server. Mail displayed a spinning gray spokes graphic next to the message “Checking connection to mail server servername“. It continued to do this until I clicked the “Cancel” button, at which point Mail allowed me to continue with the account setup.

Now when I tried sending an e-mail message, the message remained in the “Sending…” mailbox until I quit and relaunched Mail, at which point the message moved to “Outbox”. When I went into Mail preferences and clicked on “Accounts”, I saw the message “Checking account: Connecting to server…” displayed in Mail’s Activity window. When I opened Mail’s Connection Doctor, the message “SMTP connection to servername failed” appeared after a long delay.

After much experimenting, I found a solution, which is to set up the account as follows (I first removed all Mail preferences and files so as to start with a clean slate):

1. During account setup, enter the outgoing mail server information, but click “Cancel” when Mail keeps saying “Checking connection to mail server servername“. Then click “Continue”.
2. Bring up the Activity viewer by choosing “Activity” from the “Window” menu.
3. Open Mail preferences, click on Accounts, and select the account in question. In the popup menu to the right of Outgoing Mail Server, choose “Edit Server List…”.
   1. In the server list window, select the problem account.
   2. Click the “Advanced” tab.
   3. Click the red stop sign icon next to “Checking account: Connecting to server…” in the Activity window.
   4. Select “Use custom port” and enter 465 (for SSL) and leave “Use Secure Sockets Layer (SSL)” checked.
   5. Click “OK”.
4. The popup menu should now display “servername (Offline)”.
5. Choose “Edit Server List…” from the popup menu again.
   1. In the server list window, select the problem account.
   2. Click the “Advanced” tab. The password field will now be blank.
   3. Click the red stop sign icon next to “Checking account: Connecting to server…” in the Activity window.
   4. Enter your mail account password.
   5. Click “OK”.
6. The Activity window should briefly show that Mail is checking the connection and then the message should disappear.

Why all the fuss? I’m not certain, but I speculate that it’s due to the mail server in question accepting only unencrypted connections on ports 25 and 587 and only SSL connections on port 465. Mail seems to think that if an outgoing mail server supports SSL it should support SSL on all ports on which it accepts connections. Adding to the confusion is a bug in Mail that seems to prevent changes to the outgoing mail server configuration when the “Checking account” process is active.