Private Domain/POP3 - Where'd he find my EMail Settings?

[Kivin]

I'm pretty damn impressed with how sophisticated my new crack berry is. However I'm a might puzzled.
I own a domain which runs a number of web applications for personal use. I performed my BIS Email setup using an Email address available through that domain. I was surprised that it didn't ask me for my POP3 settings, and has no issues pushing my emails :-o
Just where did it find my settings O_O

[penguin3107]

BIS queries the MX record for your domain name and uses that to make assumptions as to what your POP3 server might be. It tries a handful of possible options until it finds one that works.
If it can't find one, then it will prompt you to enter one.

[takeshi]

It's pretty easy to guess POP settings in most cases.