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reject with no reverse dns

I'd like to configure my sendmail to reject messages from senders that have no reverse dns (ptr). Is there an easy way to do this via editing the sendmail.cf file?

PsiCop

Well, hopefully, you don't edit the sendmail.cf file directly. I'm saying this as a person who rolled his own sendmail.cfs for nearly 10 years - learn the m4 macro system and use sendmail.mc to generate your sendmail.cf files. I switched earlier this year, and I never want to go back.

You need to specify your sendmail version. Different sendmail versions have different capabilities.

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PsiCop

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NoelKent

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Sendmail 8.12.8, I also am running SpamAssassin version 2.64 on RedHat 9

PsiCop

Hmmm...that's a slightly-dated version. Do you have the security patches on it? Might be a good idea to upgrade to at least v8.12.10.

I'm fairly sure that SpamAssassin can reject based on the sending mailhost not having a PTR record. Personally, I wouldn't do that - give them a few points towards their SPAM score, yeah, but not outright reject.

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cgrey

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NoelKent

ASKER

I think i'll work on implimenting the different domains for pop3/smtp, currently I'm using access.db to block all ips from lacnin, and apnic, we are a small company that works only within north america and we don't really care about email from those parts of the world especially considering 95% of it we receive is spam.

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anfi

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