Trouble sending email from iPod Touch

I have My own Local ISP, I'm not having a problem from their end. I am having trouble sending my email from the outgoing mail server from my iPod Touch, I have it set up correctly.
What I wanted and tried to do is sync my composed and sent emails from my iPod Touch to my computer email Program (Apple). What I did was I plugged in my iPod Touch to my computer, clicked on "Devices" in iTunes, clicked on the Info. Tab and scrolled down to "Mail Accounts" and chose the "Sync Selected mail accounts": check box, Then I chose my ISP Pop account email check box, then chose the "Advance" section and checked all the check boxes: Contacts, Calendars, mail accounts, and Bookmarks, then I clicked on the Sync Button at the bottom. After I did this I tried sending an email from my iPod Touch, the email went to the out box and not to the sent section of my iPod Touch, my iPod suddenly stopped sending email and had little trouble getting email from my computer while my iPod Touch was "checking" its "email" with its little blue wheel spinning at the bottom of the mail iPod Touch screen, My computer email program (apple) would get the little Triangle next to the inbox. I had went Back to my iTunes, iPod Touch "Devices", Info Tab, and undid what I did and re hit the Sync Button again, I then had noticed that in the "Advance section" the "Mail Accounts" check box was un high lighted, I am not able to check it if I wanted to. Now sometimes I am able to get my email from my computer, I am able to send email from my computer email program (Apple).
Does any one have a solution and that can help solve this sticky problem? and help me refix this?
Thanks,
Trisha Foster.