We have several users that are connecting to our exchange 2013 server using outlook 2016. It seems that many of them get an error related to mailtips not being displayed. Something along the lines of "We can't show MailTips right now". Other features of outlook that rely on EWS seem to be working properly, OOF, Free/Busy are both working.
I can create a profile for the same user on Outlook 2013 and I do not get the error message about mailtips not being available.
I've run connectivity tests from the remote connectivity test, and those all pass. I've also compared the results from the autocongfiguration tests for both outlook 2013 and outlook 2016 and they are identical.
Mailtips are enabled at the organization level (they work for outlook 2013).
Does anyone have any ideas?