bulletdodgeneo
The email messages are rejected by the mail server, so they never get delivered to the server, therefore cannot be released. The executable content blocking applies to all incoming messages, so it is not possible to be selective.
You can disable exe content blocking temporarily for file types you want to receive, or perhaps use an external email address to receive them.
Alternatively you could create a webshare where an external user can upload the executable file using a web browser.