Convert a Custom Sender to a Well-Known Sender

When you have a custom sender with netblocks that match or overlap a well-known sender, you can convert the custom sender to a well-known sender. This can often happen when Agari adds new well-known senders to DMARC Protection and "discovers" the match.

When there is an exact netblock match, you can simply convert the customer sender to a well-known sender and delete the custom sender. When there is an overlap, that is, when just some of the netblocks in the custom sender match a well-known sender and some do not, you will have several options for which type of sender the netblocks will be assigned to. You make the choice of what to do, and DMARC Protection does all the work for you.

  1. Go to Configure > Manage Custom Senders.
  2. Click on a custom sender that displays the icon. This icon indicates that the custom sender contains netblocks that match or overlap an existing well-known sender.
  3. Click:
    • Use Well-Known Sender to add the matching netblocks as a well-known sender in your organization. If the netblocks overlap, instead of being an exact match, the result will be as detailed below.
    • Keep Custom Sender to leave your sender definitions as-is.

TIP: If you choose to leave your sender definitions as is, the icon will remain on the custom sender and you will have the option to convert to a well-known sender at any time in the future.

IP Address Overlap

There are three possible cases when custom sender netblocks overlap a well-known sender's netblocks. The table below explains what happens in each case when you select Use Well-known Sender.

Case Result
All of the custom sender's netblocks are a subset of a well-know sender's netblocks. The custom sender will be removed and replaced with the well-known sender in your organization.
All of a well-known sender's netblocks are a subset of the custom sender's netblocks. A well-known sender will be added to your organization with the definition of the netblocks that match the ones in the custom sender. The custom sender will remain, but its definition will have the netblocks that matched the well-known sender removed.
Some of the custom sender's netblocks are the same as some of a well-known sender's netblocks.