Krileon,
It has been thus why i asked the question, we have found a fix, i have created an auto action, that when a member is banned two things happen, one they are moved into the user group 'Banned' and then we have a newsletter subscription feature, we update this to 'Do NOT email me newsletters'
This has effectively fixed the issue.
Bit of a work around, but because we cannot check if a user is blocked or banned within the mailer this was the best solution
Thanks for support and feedback
We hope that we can assist you if you need and ask, all the best from the WTP Team