Ignoring incoming Email Subject

I have created SMTP port and want to ignore subject for incoming emails. Usually Subject should contain fully qualified service name or empty but in my case my client can not send empty subject and canot modify it to have IS service name.
Any suggestion will be appreciated.

Regards,
Faisal

when you create the port, just assign the “Global Service” and "Default Service " with the service you want to invoke, then the email subject won’t matter.