Constant "Not a Member" messages

Hello!

We have a user that has been getting a couple of "Not a member" messages every minute for the past couple of days, though they have never clicked the link. I turned off the link in Email Security 24 hours ago, but the issue has not stopped. Their email provider is "shaw.ca", and the subject line is "Please confirm you are *not* a Member of Club 848867 now", if that helps narrow it down at all.

They have had to put all emails from FTH into spam to avoid these messages filling their inbox.

Please let me know if there is anything I can do to help investigate or fix this issue.

Thank you!

-Mike
Literally Speaking #848867

Hello.

Not sure if anything was done, but the user has now stopped getting the nuisance "Not a member" emails.

Thank you, 
-Mike