Can you have multiple ptr records

Software running mail servers often expect only a single entry for each IP address. When it retrieves it, it starts treating it as a canonical name for a given hostname. And that one might not necessarily match the A record.

No such feature is available for PTR records. Table of Contents. What are PTR Records? Why PTR records are important? How to set up PTR records? Can I have multiple PTR records?

Stanislav Shymanskyi Product Manager Mailtrap. Comments 1 replies. Sign Up Now Get a free Mailtrap account, set it up in 5 minutes and start testing your emails today! Sign Up Now. Mailtrap uses cookies to enhance your browsing experience, analyze traffic and serve targeted ads. Totor Totor 2, 3 3 gold badges 21 21 silver badges 30 30 bronze badges.

I can't think of a reason that would make sense to do. PervonZweigbergk This is not what I asked, but for example, because I have several names pointing to the same IP, and want the reverse to match all of them. PervonZweigbergk Imagine a mail server that handles mail for multiple domains. You may want to use a name within the domain you are sending mail for in the EHLO command.

Certain receivers require that you have a PTR record matching the domain in your EHLO command, otherwise they won't accept mail from you. But if you have multiple PTR records, they may just pick one of them at random, and if that one does not match the EHLO command, it rejects the mail.

I know it's not what you asked, which is why I asked this via a comment, not as an answer. You'd do well to be more explicit that you're talking about the context of outgoing e-mail, which is what kasperd is speculating. A mail server is only expected to use a single name in its EHLO commands, regardless how many domains it handles mail for.

Show 3 more comments. Active Oldest Votes. Improve this answer. Elaborating on "one canonical name": in cases where the IP address could be associated with more than one entity, the most specific is preferred. In the case of a webserver with multiple name based virtual hosts, the name of the webserver itself is most appropriate. It looks like a de facto rule, as software developers started to consider that only one PTR was the norm. Am I right?

Totor Added a quote and link for a source. As an anecdote, it was recently noted that Apple has a few PTR records that are over 9k bytes worth of answers. Doubtless they aren't the only ones. This is a rather extreme example of what you can end up with when mandatory PTR record policies don't take the details of this answer into consideration.

Add a comment. Giovanni Tirloni Giovanni Tirloni 5, 3 3 gold badges 23 23 silver badges 45 45 bronze badges. How can you guarantee that a any problem isn't happening in the "infinite" number of different systems around the Internet? Just a handful have this so not a big deal to change those. Should I? Then setup conical cname records for the pop3. Most mail systems check to see if the MX record comes full circle to help reduce spamming. Most spam messages fail this circular check. If you have multiple mail hosts is it allowed by design to have multiple MX records for domain.

In this case you would use the metric or cost to select the preferred mail server. The lower the cost the more likely it is to be used. IMO In your case you probably should go through the reverse lookup table and clean out an miss matched addresses. Yea, that was just a made up domain and IP used for example Sorry for the confusing..

We do have a few domains with multiple MX records also ours being one but thinking that would be a different issue. Ok, another similar question and I think I see why I may have left these records like this over the years IN A IN PTR exchange.