The SMTP server is used when you rescue messages.
The SMTP server is the server that you use for sending email. If your email address is email@example.com, your SMTP server might be smtp.widgets.com or mail.widgets.com or something similar.
If your SMTP server requires you to log in with a name and password, check the Requires name and password checkbox and fill out the name and password fields.
Warning: Not all SMTP servers actually require a name and password. Do not use this option unless you are sure your server requires it. Check with your ISP or check the settings in your current email program to make sure. If you specify a name and password and your server does not require it, you may get an error when rescuing mail.