I need a permanent fix for the 'mail server not found' bug (iPad 2 3G)

This problem started happening on my iPad 2 (3G AT&T) about 2 months ago. I found the fix posted numerous times on this forum> delete your mail applications & reinstall them which I did (deleted & reinstalled both my gmail & yahoo accts). Same problem reappeared about 2 wks later so I repeated the fix. It happened a 3rd time this wk so I repeated this fix a THIRD time before I left town a few days ago. Here I am 3 days later & it's back AGAIN. FYI...ALL the apps are up to date on my iMac & iPad 2. Can anyone tell me when the fix for this bug is going to be released & what the work-around is?