Invalid HELO – Don’t forget your PTR

If you are handling your own mail on a dedicated server or VPS there is one step that is commonly overlooked and that is asking your host to set a PTR for you.  A PTR is basically a reverse lookup on your IP to resolve the IP to a hostname.

In an effort to combat spam, many mailservers are configured to not accept mail if the IP doesn’t resolve back to the hostname.    If it doesn’t match it’s going to bounce due to an Invalid HELO and your mail isn’t going to be delivered.

So, what you’ll want to do is contact your hosting company and ask them to set a PTR for you.    You’ll need to give them the specific IP and what it should resolve to, making sure that it matches the hostname that your mailserver uses.

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