When attempting to delete a mailing, users may receive the error:
The mailing cannot be deleted because it is in use as a previous mailing exclusion on another mailing.
Article
Number:49678
Products:
Blackbaud_CRM
Blackbaud_Direct_Marketing
This error indicates that the mailing has been used on the exclusion tab in the Previous mailing exclusions section. Once the mailing has been deleted from this section, then you can delete the unwanted mailing.