I have a few email accounts. For my Gmail account if I send an email on my iPhone, it does not show up on in sent mail on my Mac (or anywhere else for that matter). I am using Apple's Mail application and the emails I am sending from iPhone are also being sent from the mail application as opposed to using the Gmail HTML interface. Gmails sent from my iPhone do show up in sent mail when I open Gmail in a web page. Also, emails sent from my Gmail account on my Mac do show up in sent mail on my iPhone.
I only have this problem with Gmail (my primary email account). My other emails sync up fine between me iPhone and Mac.
Outgoing mail server: smtp.gmail.com
Mailbox behaviors: "Drafts Mailbox" and "Trash Mailbox" are listed under Mailbox Behaivors, but there is no "Sent Mailbox" like I have with my other accounts. I have a feeling that this is the root of my problem since I have no way of electing to have my Sent mail stored "On the Server".
Any suggestions would be greatly appreciated!
If you set up Gmail on your iPhone as exchange it works like a charm.