trouble with external communications.
Hello everyone, we recently migrated from a shared tenant to ourer own ( Company policy change of ownership) Prior to this external chat worked flawless - and we have ourer own shared Sfb envorinemtn in ourer datacenter. After htis migration we encounter only 2 user are able to communicate with external parties (everything and everyone) Rest just get a message very quickly to state "There was a problem sending this message. We have a case with microsoft going for around 1 month by now. We have phased out skype for business pointed all DNS records to 365. We are really out of context here what the next step is - we are as a business HEAVY