I have been on quite a journey of discovery over the past 12 months with identifying, reporting, blocking and permanently suppressing spammers. I am finally achieving some results and improving my process too.
To begin with it was quite a laborious process until I discovered SpamCop.net. Taking the raw source of the email and pasting it inside SpamCop means they do a lot of the heavy lifting for me. They identify the source of the email and where the domain is hosted and they will report it direct to those sources. Super easy to do and highly recommended, the service is free. Because it also provides me with the email addresses that they report it to, I will then also email some of them direct as a belt and braces and engage in a direct communication, especially with the email client provider.
This has resulted in a lot of successful unsubscribes, being added to email suppression lists and getting the offender banned from those email services. That last one is a very good feeling.
The only area that is still a real issue is Google's mail servers themselves, but thanks to my communication with some mail client companies they have pointed me in the right direction with that as well.
This is the link to report spammers direct to Google: https://support.google.com/mail/contact/abuse
Let's take one specific example of a spam message I received recently to illustrate how this process works.