email security question, sending email without active domain?

jols

Well-Known Member
Mar 13, 2004
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Is there any way to prevent email from being sent from a hosted account if it has no registered domain? For example, I know that you can use the server IP as email host address in place of mail.domain.com. So I was just wondering if email services could be effectively denied unless or until there is an active domain in the account?

Anyone?