Clickback MAIL hitting dead/invalid emails
Clickback MAIL has been hitting spam trap with email addresses which have been dead for a very long time (i.e. years) or never valid in any decade. Probably because Clickback doesn’t require pesky things like “Opt-In” or “Confirmed” subscribers but do allow purchased lists and “cold” contacts to be mailed. Seriously this is bad behavior, I wonder why no one has just blacklisted all of Clickback IPs/domains yet?
Hold on, Spamhaus DBL has (recently) partially blocked some of the Clickback sending domains but not all (yet).
Clickback loves to use domain names that make it look like they are legitimate senders, with a mash-up of mail terms including “smtp”, “server”, “stream”, “email”, “mta” and “sender”. I have mapped out the Clickback Internet net blocks and domain names scattered around various providers for those who might be interested in blocking them.
Some (partially redacted) SMTP logs, the recent ones are mostly being blocked by Spamhaus DNSbls. Others have “special treatment” applied.
May 15 X [104.245.4.244]: 550 5.7.1 X; from=<bounce@em-send.com>
May 1 X 554 5.7.1 <cloud30.clickbackmail.com[173.242.25.30]>: X; from=<bounce@cbsend.com>
Apr 27 ds11.linksvr100.com[104.245.4.70]: 554 5.7.1 X; from=<bounce@em-send.com> X helo=<smtp3.em-send.com>
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