We have a problem with our Iphones not receiving all calendar appointments from Exchange server using ActiveSync. There is a KB article out there (kb958781) that has a hotfix for this issue. My question is this, when it comes to fixing ActiveSync issues, do I need to patch all our mail servers or just the front end box that the phones talk to? thanks, Stephen

Front end server serves the request for OWA and ActiveSync. so you need to patch just the Front end servers. Vinod |CCNA|MCSE 2003 +Messaging|MCTS|ITIL V3|

This article doesnt say.Most requests to a FrontEnd server it only proxied to the backend so I would install it on both starting with FrontEnd servers.but you should really try it out in a lab first to verify.lasse at humandata dot se, http://anewmessagehasarrived.blogspot.com

Hi Stephen,The hotfix needs to be applied on both front end and back end servers. Thanks,Elvis

I agree with Elvis, apply it on both front/backend server.Regards,Funnyghost

I went ahead and patched both the owa and mail server. And it appears to have fixed our issue with calendar sync with the iphones. Next question about this... MS09-03 is a security hotfix that replaces alot of the files that I just patched. Will this break the specific issue that I just patched ActiveSync to fix? http://www.pandasecurity.com/homeusers/security-info/about-malware/encyclopedia/overview.aspx?IdVirus=205736

MS09-03 seems to contain never versions of some files as you mention. They should therefore contain the fix with activesync that solved your problem, so this should be safe to install.lasse at humandata dot se, http://anewmessagehasarrived.blogspot.com