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Continue to ChatQuery : I the mail server the client user have a good SPAM filter it should not be a problem. The SPAM will just go into the junk. If you still think that you have to make him remove his email https://vmapp.org/query/73191/I-The-Mail-Server-The-Client-User-Have-A-Good-SPAM-Filter-It-Should-Not-Be-A-Problem-The-SPAM-Will-Just-Go-Into-The-Junk-If-You-Still-Think-That-You-Have-To-Make-Him-Remove-His-Email/