We've all been there, thanks for the update.
Most likely cause will by the DNS server or the time is wrong/not set.
Also make sure that if the 2 that are not setup are the 2 58xx machines, Make sure they are on a firmware ending with .23400 or higher due to some known scancompatibility issues.
You would need to call Xerox support to get the software.
I have 3 Xerox WorkCentres (5855, 5755, 5875) in one location. I'm trying to set up Scan to Email on each of them. I'm on my second WC after successfully testing the first one. After setting it up exactly like the first one it will not work. I get a message "server address is not available" when I test the scan to email.
I double-checked all the settings I can think of.
Solved! Go to Solution.