HTC Mogul / XV6800 / PPC6800 / P4000

If I use Yahoo email to send emails it will often send 2 or 3 of the same email over an hour or so. Not all at once. It seems to just keep sending it for a while. I am not using Yahoo Go. Just regular Yahoo on a mobile device. The url looks like us.m.yahoo.com/p/mail.

Does this happen to anybody else? I am using VX6800 on Verizon.
Thanks