# If you use smtp.mac.com for your SMTP server, make sure you enable SMTP authentication in your email program using your .Mac member name and password, and make sure the email address in the From field of your email message matches your .Mac member name. If the trouble continues, switch your email program to use your ISP's SMTP server instead.
# If you're using Mac OS X Mail to retrieve your .Mac email, try changing the outgoing mail server (SMTP) to use port 587 instead of port 25 (in the Accounts pane of Mail preferences). Your Internet Service Provider might be blocking access to port 25 (the default email port). For more information, open Mail, choose Help > Mail Help, and search for "changing the outgoing mail port."
