Hello everyone,
We have an issue with some users- they reported receiving unsolicited communication on Cisco Jabber client (v.11.5.1) from external source. The first time we got this issue , we disabled federated traffic from the offending domain directly on the CUCM. However, this issue is happening again. The contact is not allowed explicitly in their Jabber client. Setting for the client are setup to allow contacts from within the company, but they have to approve explicitly all other external.
Users receives only one message, looking like a spam. Contacted Cisco support, and I was told that the following:
"Privacy settings in jabber is for Buddy Requests and not messages. There is no component in jabber prevent messages from coming through to the client. The only other workaround for the situation the customer is experiencing is to Block the offending domains(blacklsit)] or allow authorized domains(whitelist)in IM&P.
We did block the offending domain in CUCM, however these messages came second time around. Our goal is to prevent such unsolicited contacts and messages on our Jabber clients. What's interesting is that we have only users with Jabber on Mac reporting this, which leads me to believe this is a bug with this client, however I can't be 100% sure.
Any help is appreciated solving this. 
