Company I work for has sharepoint 2013 in the cloud as long as exchange (both cloud and on prem)
I have been writing some applications using C# and Exchange EWS to access site mailboxes to do things with email.
Out of the 3 site boxes we created, 2 work just fine but the 3rd just keeps saying 'Email address can't be found'
we can get into the site box through sharepoint, we can send emails to it no problem and we can send emails from it. any ideas why this box doesn't show while the others do? the 3rd box does show up in search lists (say adding it as a delegate)