Users email on iPhone keeps refreshing

I have one user complaining that his groupwise email refreshes about 2 to 3 times a day.

He notices that his email icon on his iPhone will read 200 emails then it will drop down to 0 and then count up again about 3 times a day.
This apparently just started happening to him.

Could it be to many email msgs on his GroupWise mailbox?

Datasync server version is 1.2.3 build 882


Thanks.