Receiving EventID 31855 message in the QCS Event viewer about the partner sending invalid messages. Following the process of updating the encryption keys or generating the new ones is not helping. What are the ways to resolve such problem?
This article only offers one of the possible causes that might contribute to the problem. It may not help in every case.
In this particular case mail was routed via Notes Coexistence solution which was introducing some change in the mail format. This was making it impossible for QCS to recognize message as a valid sync packet while visually it was looking normal. Once Notes solution was excluded from the mail routing the problem was solved.
