We're in a hybrid setup with Exchange 2013 and Ofice 365.
Our issue is that some users with a mailbox in Office 365 cannot send to some users with mailbox on the on-prem Exchange 2013.
I've narrowed it down to the GALs, where the primarysmtp fields are different for the same user.
On-prem GAL entry:
Office 365 GAL entry:
x500:/o=COMPANY/ou=Exchange Administrative Group [FYDI.... etc
The MAIN culprit here is of course that the user's Primary SMTP address, listed in the Office 365 GAL, does not exist on the user's mail account at all.
But why are those two GAL's different? Is that by design? Links and/or helpful answers are much appreciated.