In this article, I described how to create an authenticated SMTP in Exchange 2007/2010: http://www.itxperience.net/come-creare-un-smtp-autenticato-in-exchange/
On exchange 2013 the procedure is similar…. but with a small difference! In addition to the configuration that you can find in the article that I linked, you have to make a further change: you have to run the command
Get-ReceiveConnector "Name of the connector" | Add-ADPermission -ExtendedRights:ms-Exch-SMTP-Accept-Any-Sender -user “NT AUTHORITYAuthenticated Users”
Also on the connector labeled “Client proxy servername”
[…] At this link you will find instead the further command from having to perform to create an authenticated SMTP on exchange 2013: http://www.itxperience.net/come-creare-un-smtp-autenticato-in-exchange-2013/ […]