I’ve been working with hybrid Office 365 environments for quite some time now and liked to think that I had come across most of the weird errors, but of course just when you think that there has to be another random msExch attribute to come along and muck things up.  I came across just such a case today, presenting itself with the following error in Office 365:

Exchange: Cannot process command because of one or more missing mandatory parameters: ArchiveGuid.

I did a little digging and came across this blog post that found the msExchRemoteReceipeintType attribute to be the culprit.  I cleared the value, kicked off a full dirsync and wha-lah!  Problem solved.