Sync most recent emails only?

Setup your account as IMAP not POP3 and you'll always be accessing the most recent emails directly on the server, rather than downloading all to your phone.

Other forums mention forwarding all my email to a gmail account that uses IMAP. Is that correct, or is there another way? Thanks.

That's the only way, as Comcast does not support IMAP. In fact, that's what I do with my Comcast account. Here's a good write-up on how to set things up:

http://complexdiagrams.com/2009/01/19/imap-for-gmail-mailapp-iphone/

and once you copy wjosten's steps, on the iphone in settings:mail, contacts and calendars under mail you can set the number of messages to show. there is a choice of 25, 50, 75, 100 or 200.

Message was edited by: Barry Porter1

Message was edited by: Barry Porter1

Your replys will be coming from your Gmail account. Yes, you can forward as many accounts as you want to your Gmail account.

Look at it this way, to do what you want requires an IMAP account. Comcast does not support IMAP. So, you either obtain an IMAP account, keep your existing Comcast account/accounts, forward everything to your Gmail account or live with the limitations of a Pop account. Pop was never designed to access mail on more than one device.

Can I set up more than one IMAP account on the iPhone?

Yes.

Also, my business email account would need to be IMAP on my PC AND the iPhone, correct?

For IMAP to work as designed(keeping mail in sync on multiple devices), IMAP must be enabled on every device you use to access mail.

Are there any implications of switching from POP3 to IMAP for an existing email account?

Yes, your mail will now be in sync on all of your devices, and you will gain the ability to create folders directly on the server which will be accessible on all of your devices and kept in sync.