I took the paragraphs below from another Thread on this site, it has worked for me so far.
"I think i may have found a solution accidentally this morning (it works for myself at least). What i did was to delete my AOL account off the phone and re-set-up using the 'manual set-up' button as opposed clicking 'Next' and letting the phone doing it's own thing on auto.
As it happened the info in the Manual set-up method did not require you to input any of the information about servers or ports etc (may have had taken it from my auto set-up), so you just click through the set-up assign a name to your account and then hey presto your email account is set-up.
You then go into the settings for the account and tweak to your requirement and then give it a whirl.
Lo-and behold mine has finally started syncing on it's own accord and pretty darn quick too.
I tested deleting from my desktop and saw the same email delete from my phone inbox. I then tried a delete from the phone and the mail in question vanished from my desktop inbox."