How would knowing spammers email address improve spam detection algorithms?
Please accept my apology as it is not really a data science answer.

A lot of spammers are using spoofed emails address as sender, so that field alone might not be very helpful as a dimension. The number of possible values also could make it impractical to be used (i.e., 1 hot-encoding) as a feature unless you preprocess it somehow. Sender domain, sender server reputation scores, etc. would probably be more helpful than the email address by itself.

How spammers spoof your email