Trying to delete a Send Port, you get this error:

SendPort ‘sp_ABC’ is being referenced by one or more TPM Parties. Please remove the Send Port reference(s) from the parties and retry deleting the Send Port (Microsoft.BizTalk.ExplorerOM)

By the way, TPM stands for “Trading Partner Management”.

Explanation

When you use EDISend Pipeline, BizTalk needs to know which Party to use, in order to put the correct identifiers and other fields in the ISA and GS segments of the EDI file.

One of the most common techniques for identifying the Party is to put the SendPort name in the X12_Agreement (found under “Parties” and then usually the name of the vendor or trading partner).

This creates a foreign-key relation or dependency in the database, and the SendPort cannot be deleted while it is being used in the X12 Agreement.

Parties can be found here in the BizTalk Admin Console. On the right, you will see a list of your trading partners (they might be customers or vendors for example):

Under the selected Party, choose the X12 agreement, and at the top, select the tab that says from your company to the trading partner. Click on “Send Ports” on the left. If you still want to delete your SendPort, find it in the list of SendPorts (one below is blurred to hide the name), then click the remove icon or word. That only disassociates the SendPort from the Agreement (it doesn’t actually delete the SendPort from the system).

But wait, there’s more! When you put a SendPort on an agreement, it get’s associated to the party as well. So there is a second place you have to remove it.

Now you should be able to go back to the Application and delete the SendPort.

If you are not sure which Party to select above, then I have a T-SQL query that cross-references Send Ports and parties.