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Using your email accounts

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8. POP before SMTP overview

"POP before SMTP" is a method for authenticating users before they send mail through a mail server. It is primarily used to cut down on abuse and misuse of open mail servers. With "POP before SMTP", you can now securely send email through the SMTP server that is available at your hosting account and rest assured that other parties are not using your SMTP server to send unauthorized email. Unauthorized users are automatically denied access, and most legitimate users will not notice any difference in service.

SMTP, the Internet's mail transmission protocol, until recently had no authentication capabilities. Many of the older mail clients do not support the new SMTP authentication protocol so there is no reliable way to determine if a particular sender is allowed to send mail to an external address. Unlike a traditional ISP, we cannot determine if a sender is a customer by checking their IP address.

However, all of our customers hosting accounts have mailboxes which are accessible through POP3. POP3 is a mail retrieval protocol, and does have authentication built-in. Therefore, any customer who legitimately accesses a mailbox on our servers via POP3 is automatically authorized, for a period of up to fifteen minutes, to send outgoing mail through our relay service.

How do I know if my mail program does POP before SMTP automatically?
You can run a simple test. Using your normal mail setup, just send mail to a non-MetaPros account. Most mail clients show status messages while they're handling mail. Watch the messages to see if it checks for new mail before sending the message. If it does, you're covered. If it doesn't, look through your program options for a "check mail before sending" or similar option. Some clients have a "check and send" button in addition to a plain old send button. In all cases, the client must check for new mail before attempting to send mail.

What can I do if my mail program doesn't work properly with this setup?
You have a few options. You could switch to a mail client that will work with our configuration or if you're stuck on your current client for one reason or another, you could just make a minor configuration change instead. Use your Internet Service Providers (ISP) SMTP server for sending mail rather than using MetaPros'. You would still retrieve your mail using POP from our server, but any outgoing mail would be sent through your dialup provider's mail server. This bypasses any authentication restrictions. You'll just need to know the address of your ISP's SMTP server (usually mail.yourisp.com). Then find the option in your mail client where you can set the SMTP or outgoing mail server name and change it. Be careful not to change the POP3 or incoming mail server name, or you won't be able to retrieve your MetaPros mail. If you need help with this step, ask your Internet Service Provider how to configure your mail client to use their SMTP server.


Updated: January 7, 2001

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