Mutt, GMail, POP3 and IMAPS

[Paul Fortin]

I'm using Mutt to read and post to this mailing list.  Here is what I added to my .muttrc file:

set imap_user = "pauldesktop at gmail.com"
set smtp_url = "smtp://pauldesktop@smtp.gmail.com:587/"
set imap_pass = "---"
set smtp_pass = "---"
set from = "pauldesktop at gmail.com"
set folder = "imaps://imap.gmail.com:993"

However, I'm scared...because it's working. :)

I'd like to ask a few questions to try and get my head around what it is I'm doing, exactly.

Does my .muttrc file determine how I _send_ mail?  Before adding this stuff to my .muttrc I didn't have 
anything listed and it was using sendmail...how, I'm not sure.

Am I now sending mail through google's smtp server?

What is IMAP?  My .fetchmailrc file has an entry for gmail, but it is as follows:

poll pop.gmail.com protocol POP3 and options no dns user "pauldesktop" password "---" options ssl

So, am I using POP or IMAP?

I'm sorry if I sound completely ignorant.