iOS e-mail issues

I am having the same problems as the users here and here where an iPhone and iPad using the same e-mail will randomly get “Server has stopped responding” errors without any change of settings. These errors will persist until the account is completely deleted and then re-set up where it will work for maybe 5 days to a week before refusing to connect again. Like the users in the other two threads there is no change to the settings to spur this on. The devices belong to my boss who is compute illiterate, travels often, and relies on his iDevices and if this happens when he’s out of the country he’s boned because he doesn’t understand how to set it all back up correctly.

Was there any investigation as to why this problem continues to happen for the last two users? Any idea why this keeps happening to my boss sporadically?