no more pushing blackberry mail through Yahoo!

a few months back I had a problem when using gmail's filters to foward mail to my tmobile blackberry... if someone would send me a attachment over 5mb's tmobile would return the mail to sender... the gmail filters would think that address isn't working anymore and then stop forwarding...

so what i did was fwd gmail to yahoo and push mail from yahoo to my blackberry... that strategy worked and stopped the problem of large attachments from stopping gmail filters to my tmo.blackberry.net address...

however that solution brought about a problem because Yahoo push mail was not at all timely... there times when I would get my email 4hrs to 8hrs later... not exactly pushmail
when I contact RIM their reply was:
"We have gone back to how the system used to work and that is based of a 900 second (15 minutes) polling interval until we can get the issue resolved between Yahoo email server communicating with our systems, the Yahoo Mail Server are suppose to notify our mail system when there is a new email in your inbox, but they have not been doing that on a consistent basis, so that is why we have gone to a consistent interval of 900 seconds."

Tmobile has recently upgraded the attachment size limit to 8MB... thereby reducing the chance of that happening... I'm now on Sprint and their attachment limit is 11MB so that's sure not going to happen... now the mail can go from gmail to blackberry without a middle man...

not sure but does Gmail allow pushmail to the blackberry? does anyone know?