Upgraded to 4.0/4.1 using 3Gs and now can't send emails!

[simonlynch]

I have a 3Gs - I upgraded on itunes 3 days ago to maybe 4.02? and this evening to operating system 4.1. However I am having a problem with my email for the past 3 days and thought that this might cure the problem... but no. I can receive emails but cannot send any. The mail is a yahoo.com account and I have tried everything...i'm now thinking of reverting back to the factory settings on itunes - i suppose this will be an operating system begining with a 3 - but will this solve my problem?
I would prefer to keep using 4.1 but if there's no solution to the email problem i'll have to revert!
any suggestions please!

 

[JW Pepper]

I have upgrade to 4.1 and now cannotsend emails. Jalap havereally short battery lifewhich I assume isit trying to send all the time. My phone is the 3GS

My mail is .me and I ca 't send.......