Below issue noticed intermittently for one user while attempting to send email
Whenever user A attempts to send email or meeting requests to user B in same domain, below issue is noticed.
However , issue not observed whenever user attempts to pick the user from GAL
We have removed the entry from NK2 . Enabled online mode and enabled cached exchange mode
Issue reoccurs after few days.
Today when issue reported , we checked and found that the said issue could not be reproduced.
Both the users are in office 365 in same domain.
Issue has not occurred in OWA.