Our company wants to set mobile phone numbers in AD using the mobile phone field. When this gets used I know that at least internally, when you click on someone's name in Outlook you can see all of that phone information that's in AD and linked to exchange.

My question is, will someone outside our organization be able to see that phone information the same way?

Hello

from outside no.

Our company wants to set mobile phone numbers in AD using the mobile phone field. When this gets used I know that at least internally, when you click on someone's name in Outlook you can see all of that phone information that's in AD and linked to exchange.

My question is, will someone outside our organization be able to see that phone information the same way?

The only way they would be able to see it is if you had a trust between your two organizations OR you have an automated way to put a signature on an email and it is configured to provide that information.