You may have one or more Sender Domains associated to your account, in this example the sender domain is @guru.vcab.com. This is a sub domain of @vcab.com.

The drop down next to Sender Address Dynamic allows you to select a field against the contact record to use as the sender email address.

This example uses a field called crmAccountManager.

So when the Email is sent the Contacts Account Managers Email address will be populated in the Sender address. However the data that is held in this field is not [email protected] which is the Account Managers true email address. This is because @vcab.com is not set up for use with CommuniGator. The data has [email protected] as this is the email address that is authorised to be used with CommuniGator.

If you where to populate [email protected] into the sender address the emails will fail to send from the system.