User can't receive external email

[Jcx500]

So...

I have a new user who can send and receive internal emails fine. But as soon as its an external address they just bounce back. The user is the same as all other accounts in 0365 and exchange properties are the same

 

Any ideas?

 

Thanks

[bald_pig]

What does the bounceback say?

 

That's going to tell you what is stopping the mail.

[Jcx500]

Turns out our service account what syncs AD to our email filters expired. If only I thought about that before It would of saved me hours !