The fix for Gmail 550 5.7.25 is a reverse DNS record for the IP address your mail leaves from. Ask whoever owns that IP, usually your internet provider or web host, to set a PTR record pointing to a hostname, and make sure that hostname points back to the same IP. If you can't get one, stop sending from that IP and route the mail through your real email provider instead.
What does Gmail 550 5.7.25 mean?
Gmail 550 5.7.25 means Gmail blocked your message because the sending IP address has no valid reverse DNS record. Google's Gmail SMTP error reference gives the text as "This message was blocked because the sending IP address doesn't have a PTR record, or the forwarding DNS entry doesn't reference the sending IP address." It also lists a softer 421 4.7.0 version for the same problem. The 550 version is permanent.
A PTR record is the reverse of a normal DNS record. A normal record turns a name into an IP address. A PTR record turns an IP address back into a name. Gmail checks both directions, and they have to agree. Google's email sender guidelines tell all senders to "Ensure that sending domains or IPs have valid forward and reverse DNS records, also referred to as PTR records."
What does a 550 5.7.25 bounce mean for my business?
A 550 5.7.25 bounce usually points at one machine, not your whole email. Something in your business, often a website form, a scanner or an old office server, is emailing customers straight from its own internet address. If it's your contact form, you're losing leads you never hear about. If it's the scanner, documents aren't arriving. Your normal Microsoft 365 or Google Workspace mail keeps working.
Who can fix a missing PTR record?
The only party who can set a PTR record is whoever controls the IP address. Your domain registrar can't do it, and adding a record in your own DNS zone won't help. Reverse DNS lives with the IP's owner:
- A web server or VPS: your hosting company. Most have a reverse DNS or rDNS setting in their control panel, or will set it by ticket.
- An office server or device on your business internet: your internet provider. Many only set PTR records on a static IP.
- Microsoft 365 or Google Workspace mailboxes: already handled. Their sending IPs have PTR records, so a 5.7.25 bounce on normal mailbox mail means something else is sending.
Which senders usually cause 5.7.25?
The senders that usually cause 5.7.25 are the ones that send mail straight from their own IP instead of through your email provider. Say a Kalamazoo shop has a website contact form on a cheap VPS, a scanner that emails PDFs, or an old on-site server sending invoices. Each one may hand mail straight to Gmail from an IP with no PTR record, and only that one device's messages bounce.
How do I fix 550 5.7.25 step by step?
You fix 550 5.7.25 by finding the sending IP and either giving it a matching PTR record or taking it out of the path. In order:
- Find the IP. It's in the bounce text.
- Identify the device. Match that IP to a server, website host, scanner or app.
- Ask for a PTR record. Contact the host or internet provider and request a PTR record pointing to a hostname such as mail.yourdomain.com.
- Add the forward record. In your own DNS, point that hostname at the same IP so both directions agree.
- Or relay instead. Better for most small businesses: set the device or form to send through your Microsoft 365 or Google Workspace account, or a mail service, so it uses their IPs.
- Authenticate the sender. Whichever path you pick, cover it in SPF and DKIM. The 550 5.7.23 SPF guide shows how to add a sender without breaking your record.
- Test. Send to a Gmail address, open the message, choose "Show original," and check that SPF, DKIM and DMARC pass.
If the IP is buried in a long bounce, paste it into the free reader on the no PTR record page at postmortem.report. It runs in your browser and names the error. Got a different code? The email rejection error codes guide lists every code with its own fix page.
When should you get help with a reverse DNS bounce?
You should get help when you can't tell which device is sending, or when moving it to your mail provider means rebuilding SPF and DKIM. If you run a business in Battle Creek, Kalamazoo or anywhere in Southwest Michigan, the Parallax DMARC audit service finds every system that sends as your domain and gets each one authenticated. Call (269) 460-1772 or use the contact form and tell us what the bounce says.