During set up of my proxy installation I had intermittent problems with Active Sync on some mobiles. After adding the following global parameter, all connected flawlessly: ignore_expect_100 on Then on the cache_peer you should add connection-auth=on to forward NTLM and forceddomain=exchangehostname to send the very same hostname in the request as the Exchange https connector expects clients should use (fqdn of the certificate name on Exchange IIS). > -----Original Message----- > From: Who Me [mailto:whome9988@xxxxxxxxx] > Sent: Friday, January 27, 2012 3:08 AM > To: John Hardin > Cc: squid-users@xxxxxxxxxxxxxxx > Subject: Re: Reverse Proxy for OWA - issue with > SSL and ActiveSync > > Thanks - I will take a look at that tomorrow. In the > meantime, I was able to test with an iPhone (an old one... > the iPhone3) and oddly enough, it worked. > > -And yet Androids still won't work unless you select 'accept > any ssl' which certainly isn't a secure move.