troubleshooting Question

On-Prem and Office 365 GALs are different

Avatar of Joergen Lind
Joergen LindFlag for Denmark asked on
ExchangeMicrosoft 365* global address list
8 Comments1 Solution63 ViewsLast Modified:
Hi everyone.

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:
x500:/0=ExchangeLabns/.... etc

Office 365 GAL entry:
SPO:SPO_436334 etc
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.


Bjorn Dirchsen
Shreedhar Ette
Technical Manager
Join our community to see this answer!
Unlock 1 Answer and 8 Comments.
Start Free Trial
Learn from the best

Network and collaborate with thousands of CTOs, CISOs, and IT Pros rooting for you and your success.

Andrew Hancock - VMware vExpert
See if this solution works for you by signing up for a 7 day free trial.
Unlock 1 Answer and 8 Comments.
Try for 7 days

”The time we save is the biggest benefit of E-E to our team. What could take multiple guys 2 hours or more each to find is accessed in around 15 minutes on Experts Exchange.

-Mike Kapnisakis, Warner Bros