I see both of them as an option in my email client, but what do they do?
Both the POP3 and IMAP protocol are methods that a client program
can use to connect to an email server and check for mail, but the
difference is in the method they use: POP3 connects just long enough to
download a copy of the messages to the client, then (usually) deletes
the messages from the server and logs off, whereas IMAP connects to the
account and displays the messages on the server until you log off.
There's
advantages and disadvantages to both: for one, POP3 connections take up
less server bandwidth than IMAP. The POP3 connection lasts long enough
to download any new messages before logging off. Whereas with IMAP,
the connection remains until the email client is closed, or the mail
server times out the connection. This is why most commercial ISPs only
allow POP3 connections. Since messages downloaded via POP3 are
downloaded to the client, they're always available on that computer,
even if you're not connected to the Internet. However, if anything
happens to your computer and those messages are deleted, there's nowhere
else to retrieve them.
IMAP, on the other hand, has the
advantage of the messages staying in one location: the server itself.
This means that you can login to your account anywhere, with any IMAP
client (or via webmail, like with WorldClient), and all your messages
will be there. This also means that you don't have to worry about
backing up your messages on your local machine; if something happens,
simply reconfigure the account to connect to your account via IMAP, and
they'll show up again. However, if you cannot access the Internet, you
cannot get to your messages, unless your client saves a local copy of
messages you read (such as Outlook or Outlook Express).
Additional Comments
Note that IMAP is only available in MDaemon Pro.
Related Articles
KBA-01365 Setting up Outlook/Outlook Express to use IMAP