[ALUG] Blackberry vs Cyrus

I have a customer running Cyrus IMAP and Postfix. They have users with Thunderbird clients on their desktops and some Blackberries using the BIS service. They are complaining that sometime emails appear on the Blackberry 10 mins before they appear in their mailbox on Thunderbird. Apparently the BB is polling every 5 mins, and Thunderbird every minute Any ideas what may be causing this delay? Many thanks, Stuart __________ Information from ESET Mail Security, version of virus signature database 6172 (20110601) __________ The message was checked by ESET Mail Security. http://www.eset.com