Office 365 synchronization fails:
Failed to add 1 user(s): - firstname.lastname@example.org (The string supplied is too long to be a phone number.)
Phone number validation failure on the OA side.
Identify the reason why the phone number cannot be accepted by OA platform. It could be done in this way: 1. Sign into CCPv1 under a test customer; 2. Try to enter "problem" phone number to the "Telephone" field of user contact details; 3. Obtain the exact error;
For instance error can state: Error: Area code can't be longer than 5 symbols.
Modify the phone number accordingly.