Test for blank subject line or unknown sender

[sillyme]

I have tried to test for a blank subject or sender in the content filter but can not seem to get a match. Is there a way to do this?

Thanks

[Code Crafters]

There isn't an easy way to do this. The only real way is to add a content filter condition for:
NOT - Subject Header Line - String Contains - "a;b;c;..." (not case sensitive)

Note that this is different to :
Subject Header Line - String Does Not Contain - "a;b;c;..." (not case sensitive) - WRONG

The SMTP sender can be checked for being blank in the same way.

To detect if a subject line exists you can do:
Any Header Line - String Starts With - "subject" (not case sensitive)
or:
NOT - Any Header Line - String Starts With - "subject" (not case sensitive)