Alternatively, from your profile, you can set your presence to Do Not Disturb to block chat notifications and let your contacts know you are currently unavailable.

I have a user that is receiving missed conversation notices in her outlook from to other users in the organization saying 'Need Skype for Business? Install it on all your devices'. The users tagged as the sender's of this message are not initiating this conversation with the recipient of the message.

All users are on Skype for business, Office 365 2016. It is only one user receiving the message and two specific users accounts sending the message. I have look here on spiceworks, Google, all over the place but I cant seem to find anything about this anomaly.

Its not critical obviously but it is very annoying for the user receiving the notices and I am going crazy trying to figure this one out. Anyone seen this? Well you've seen the consequences, you need to get your cert working in order to get all exchange services working properly, have a read through these links, hopefully you will get something from them that will help you in this situation but ideally you should have a 3rd party cert from someone like Globalsign and it should be applied to your Exchange server.