Can get mail via wifi but not when it's turned off...what am I doing wrong?

Hi,

I've set up my email account following the instructions on the phone...everything worked fined when wifi is turned off but the second it's off I get a warning from my phone saying..."Cannot connect to the incoming mail server. Be certain that the server name is correct, then try again to send and receive."

Btw the incoming mail server is correct.

What am I missing here?

Any help would be appreciated?

Now I've set up my accounts via the phone. I am on a Mac so I can't use the set up cd that came with the phone. I am also with the Telus network in Alberta, Canada.

I am also trying to figure out how to delete an email account that is set up as well. Haven't figured that one out and haven't been able to find a solution.

Thanks in advance.

Rob