I guess fax alias is what it is called. And I'm playing on an old system, Exchange 2010.
Here's the use case. Client has signed up for an electronic fax system. To send faxes the users simply send a document as an attachment to <faxnumber>@ourdomain.fax.efaxprovider.com
I was hoping to make it as easy as possible for the users to fax so I was hoping to setup an alias or rewrite or something that would take messages addressed to <faxnumber>@fax.ourdomain.com and 'rewrite' them to <faxnumber>@ourdomain.fax.efaxprovider.com and send them out.
Or maybe even in Outlook addressing to fax:<faxnumber> and it would send to <faxnumber>@ourdomain.fax.efaxprovider.com.
I've done a bunch of searching and I found info on rewriting inbound and outbound addresses for recipients, but can't find anything like the above scenario.