I am really having a weird issue.
one user let us say USER A@company.com from my company is getting calendar invite from user B@yesmail.com from yesmail domain to his outlook 2013 as plain text while other users in his department and infact everybody is getting proper calendar invite from user B @yesmail.com except USER A
I uninstalled and reinstalled office, outlook, redid his outlook profile unchecked plain txt in trust center checked addins, rules on USERA
and send test calendar invite from google to USERA@mycompany.com and it worked fine also USERA is getting proper calendar invite from everybody else.
but WHEN USERC OR USERD @yesmail.com sends calendar invite to firstname.lastname@example.org it is comes as proper calendar invite so calendar invite from yesmail domain is coming fine.
so what is wrong with that particular userB from yesmail who send calendar invite and it is coming as plain txt to the USERA@mycompany.com