Regrettably, throttling our IOS 6.1 users did not resolve the nightly issues.

MAPI / CDO upgrade is on the table for the weekend, but I wanted to get your thoughts on CAS Arrays. Both our MAPI profile and EWSCASURL/EWSSCPURL point to an NLB'ed address. Would you recommend pointing at a single CAS for those, or is the method we're using supported? We'd had no issues up until this month with pointing directly to the load-balanced address, but finding solid documentation is somewhat tricky.

Oooh, another possibility: http://support.microsoft.com/kb/2810616.

Endless!