what one should know about email and wordpress (SMTP Wp_mail and the likes)

Hey, so I’m new to wordpress, and I’m wondering if someone could explain what all one should know regarding email in wordpress and how this relates to mail on a hosting server. Let me tell you what I know so you can tell where I’m at. Basically I understand that there are two main protocals when dealing with mail. Smtp and pop3, the first for sending mail, tha latter for receiving it.

I know that most hosting servers use port 25 to send mail. But presumably some don’t.. is this something one should configure in to worpress somehow so wordpress knows the correct port to use with wp_mail? Also how exactly does wp_mail interact with smtp, and does php’s mail function use smtp as well–as you can tell I’m a bit confused-also what are the most common problems that come up, in this regard for troubleshooting a website. Like I’m starting out in webdesign, what are some of the most common problems I might run in to when setting up email in wordpress (and on hosting servers) for a client?

Thanks