I have set up a Postfix Dovecot email server on my Vultr. And I'm getting following message from Google:

   gmail-smtp-in.l.google.com said: 550-5.7.1
     Our system has detected that
    550-5.7.1 this message does not meet IPv6 sending guidelines regarding PTR
    550-5.7.1 records and authentication. Please review 550-5.7.1
https://support.google.com/mail/?p=IPv6AuthError for more information 550
    5.7.1 . e2-20020a05622a110200b0041203888045si7330616qty.45 - gsmtp (in
    reply to end of DATA command)

So I need a reverse DNS record add to my Vultr. I googled how to do that, and it shows me that I might need a host and value for reverse DNS. However, the Vultr page shown as this vultr page So the Reverse DNS is editable, but only have one text box. How could I add both name and value in one text box?

Do I need to create a ticket to make a PTR record? Or I could actually make a Reverse DNS in this single textbox? If I could, what should I type in?

This is my DNS server configuration, I'm not sure if it is correct for reverse DNS.

Type            Name             Data             TTL
TXT              @             mail.xxxx.com      1 hour
  • 1
    if you don't (g/h)ave a interface from the owner of the network to set one. Yup you will have to do to contact them. a txt record is just a plain text information but does nothing to the MX entry
    – djdomi
    Aug 30, 2023 at 4:58

1 Answer 1


In your example, you'd simply enter your mail server's host name, eg mail.xxxx.com in the Reverse DNS box.

Essentially you're making sure that if your A record for mail.domain.com points to, then if someone does a reverse DNS lookup on then it will point back to mail.domain.com, so the two match in both directions.

While technically there's a Name and a Value element to the PTR record, that's really only relevent where you're directly accessing the DNS server.

Within DNS the ISP will have a reverse zone, for instance for, within which all the reverse records for that range will be configured. So if it was being manually configured they'd create a PTR record with a name of 123, and a value of mail.domain.com. Within the web UI that's not needed though, since they already know the specific IP address you're updating, so that's already taken care of by the Address field, and all that is left is to tell it where to point.

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