The document provides solutions for resolving a Mac Mail Port 0 Error that prevents an email client from retrieving emails. Some potential fixes include using the Mail Connection Doctor, changing draft message settings, using a custom port number for the outgoing SMTP server, making a new email account, executing a Telnet test, waiting for email servers to be less busy, and checking the email address and password for accuracy.

1. Mail Port Error interrupts communication with the email
server. Mac email client program shows Mac Mail Port 0
Error and fails to retrieve emails. The following solutions
would be helpful under such circumstances..

2. Use Mail Connection Doctor
(Open Mail. Click Window | Connection Doctor. Does a spinning gear
appear in the window? If yes, click Window | Activity.)
Change draft message settings
(Open Mail App, click Preferences | Accounts | Mailbox Behaviors.
Uncheck the box labelled “Store draft messages on the server”.)
Use a Custom Port
(Click Mail Preferences | Accounts | Accounts Information | Server
Settings | Outgoing Mail Server (SMTP) | Edit SMTP Server List |
Advanced. Select “Use custom port” option. You won’t receive Mac
Mail Port 0 Error again.

3. Make a new account on OSX
Mavericks
(Open Apple Mail, select “Add another mail account” option. Click
Continue. Specify your name, email id, password and click Create |
Next.
Execute Telnet Test
(Click Applications | Utilities | Terminal. Type “telnet
smtp.gmail.com 25” (without quotes) and press
ENTER.)

4. ESP email servers
could be busy. Wait for few hours and try again to avoid
Mac Mail Port 0 Error.
Check your email id and password
Either of them could be incorrect.
Fix Mac Mail Port 0 Error