With SMTP, Demon will try to deliver all waiting mail for your domain as soon as you go online. Once it has been delivered, it is automatically deleted at Demon. SMTP is especially suitable if you always receive your mail on one machine. If you are splitting mail between several mailboxes you may need to use SMTP to get this to work properly, although some software, such as Turnpike, will get this right with POP3 as well.

POP3 (Post Office Protocol version 3) is an alternative system for mail delivery that allows you to request mail, rather than wait for it. POP3 commands allow your machine to check what mail is there, to request delivery and to delete the mail. Therefore programs can offer facilities such as "browse" (you choose what to download) or "leave on server" (you choose what to delete). These types of facilities make POP3 useful if you do not always access your mail from the same machine.

Demon's implementation of POP3 is unusual in that, like SMTP, it allows you to use a variety of usernames (or "mailboxes") providing your software supports this. This allows you to collect some, but not all of the mail for a particular domain.

Turnpike (like a few other mailers) allows you to choose either protocol for receiving mail. Many mailers, including Netscape Mail and Outlook Express, do not offer mail reception by SMTP - so you will have to set these programs up to use POP3 (see section 1.8).