Document information

Document ID:4663
Subject:Resolved IP in HELO string does not match with Sender IP
Creation date:12/14/15 4:35 PM
Last modified on:12/14/15 4:35 PM


Resolved IP in HELO string does not match with Sender IP

Problem

Some emails are being rejected for the following reason.
Resolved IP in HELO string does not match with Sender IP

Explanation

When a sender SMTP server connects to your email server, it sends a HELO string, which looks like:
EHLO mail.senderDomain.com


Among other email etiquettes, the domain name present in the HELO command should match with the sender's IP address. For example, if an email originates from 200.199.198.197 the host name mail.senderDomain.com should resolve to this IP. If it resolves to a different IP address, Xeams is going to assign a score to this message.

Most legitimate email servers will use a matching host name in the HELO command. If you see a good email getting this score, consider letting the sender know that their email server is not configured correclty.

User comments

Posted by dcol on 6/7/16 6:12 PM

I find this is a common occurrence with local email. To fix, just add the local LAN to the whitelist. ie 192.168.1.*

Posted by Robert Eckert on 2/20/14 4:39 PM

I use DynDNS which routes my email through their mailhop servers to my server, so all emails I get come from one of their servers rather than the email server. can I configure this rule to have a lesser weight or to filter only emails coming via the mailhop servers

Posted by Robert Eckert on 2/20/14 4:39 PM

I use DynDNS which routes my email through their mailhop servers to my server, so all emails I get come from one of their servers rather than the email server. can I configure this rule to have a lesser weight or to filter only emails coming via the mailhop servers


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