We just got an O2 Xda IIs at work, so you can expect a few posts from me as I explore it's features :)
Anyway, I wanted to get it to download mails from Gmail with Pocket Outlook. It was actually quite easy to set up, just set the servers up and away it went. But there was a problem, whenever it synced with Gmail, it deleted all the messages that were already in the Inbox! Pretty damn useless if you ask me.
After a bit of googling (there's a joke there somewhere), I found this post. In it, Ej mentions that you can tell Pocket Outlook to only download the headers (plus a bit of the body) and that seemed to work for me. But he also mentions that it still downloads the whole body, even though you only tell it to download 2KB (or whatever). But that didn't seem to be the case for me. Perhaps I have a newer version of Pocket Outlook, or maybe Gmail has been updated since that post. Anyway, I changed it to 25KB, since I don't really care about mails bigger than that.
I don't know if it's a bug in Pocket Outlook or in Gmail's POP3 implementation, but if I had to guess, I'd have to side with Pocket Outlook on this one. It doesn't do this with our internal POP3 server, and apparently it works OK with Yahoo (though I haven't tried) so there must be something that Gmail's POP3 implementation does that Pocket Outlook doesn't understand.
Well anyway, it's working "good enough" for me now, and hopefully someone else will find this useful...