We have recently been rolling out the latest version of AVG anti-virus for a couple of clients and everything appeared to go smoothly. The upgrade experience was a good one with the new AVG Business Anti-Virus 2011 installing on the servers and desktops with minimal interaction and no crashes, which is always nice. A couple of days later though we started getting reports from users at both sites complaining about their Exchange email not being delivered to either their iPhones or iPads. Emails were only arriving at the mobile devices once they had been opened in Outlook or Web Access.
A look at the server logs revealed no errors, which would have been picked up by us in any case. The ActiveSync logs were much larger than usual however, with some of the logs running into the 100’s of MB, all showing unsuccessful attempts by iDevices to collect email.
Of course the only thing that has changed on both servers is the Anti-Virus so the answer must be there, and a quick look at the Advanced Settings revealed the answer. We looked at the Email Scanner component and noticed that Proactive Scanning for incoming messages was not enabled by default, meaning that emails would not be processed by AVG until someone had opened them within Outlook. So we filled in the checkbox, and applied the new setting, as shown below.