Solved gmail blocks my server?

[drpaneas]

I tried to a new user to my cloudron, that her e-mail address is user@gmail.com. She never got the message -- not even in spam folder. Here's what I see:

{
  "ts": 1611591463339,
  "type": "bounce",
  "direction": "outbound",
  "uuid": "C8581E52-4E8A-4DBB-A8D1-329E9967ACB4.1.1",
  "mailFrom": "<no-reply@example.org>",
  "rcptTo": [
    "<user@gmail.com>"
  ],
  "details": {
    "message": "550 5.7.1 [123.123.123.123] The IP you're using to send mail is not authorized to send email directly to our servers. Please use the SMTP relay at your service provider instead. Learn more at  https://support.google.com/mail/?p=NotAuthorizedError f3si14251915wre.102 - gsmtp"
  }
}

So the mails are blocked. Any ideas how to resolve this?

PS: I have edited the message so 123.123.123.123, user@gmail.com and example.org are not the real data.

[nebulon]

For a start, test your setup with https://www.mail-tester.com/ this usually reveals the root cause.

[atridad]

@drpaneas When you check the DNS status for the email domain, does it show that the email is blacklisted?

[marcusquinn]

A couple of other handy links:

• https://mxtoolbox.com/emailhealth
• https://www.warmupinbox.com/

[drpaneas]

Thank you all very much for the links and the tips. Using the mail tester I found out that it had an error with authentication:

Your IP address $IP is associated with the domain $somenumber.versanet.de.
Nevertheless your message appears to be sent from mail.example.com.

You may want to change your pointer (PTR type) DNS record and the host name of your server to the same value.

This is not something I can change, since this comes from my ISP I guess.

I setup a relay at sendgrid and this issue seems to be gone. as the IP (thanks to CNAME) is associated also with sendgrid.

I tested it now and the mails gets delivered fine to at least 3 gmail accounts I tested. So far, they deliver in the normal folder -- not the spam -- but I don't really care for it. As long as the mail goes somewhere, I'm happy.

PS: Yes, I checked my domain at it seems to already be marked as spam or untrustworthy by Spamhaus ZEN and RATS NoPtr .

[marcusquinn]

@drpaneas With Hetzner, you go to the server > Networking > Edit Reverse DNS.

For your local ISP, I have no clue, maybe your VPN relay solution would work.

For interest I use Elastic Email as an alternative to Sendgrid, I realise there's little difference if you are within free tier volumes but just to bear in mind if every you have Sendgrid issues and need to try an alternative.

[drpaneas]

@marcusquinn thank you very much

Is there any way to mark this thread as solved or a moderator/admin has to do it?

[girish]

@drpaneas done. But I think you can click the 'gear' button in this post's header and then 'ask as question' and then click on gear again it has a 'mark as solved' option.

[jdaviescoates]

@drpaneas said in gmail blocks my server?:

You may want to change your pointer (PTR type) DNS record and the host name of your server to the same value.
This is not something I can change, since this comes from my ISP I guess.

It normally comes from your VPS provider, not your ISP. And you can normally change it.

More info here:

https://docs.cloudron.io/troubleshooting/#ptr-record

[drpaneas]

It normally comes from your VPS provider, not your ISP. And you can normally change it.

@jdaviescoates I have cloudron installed at home.

[p44]

@marcusquinn said in gmail blocks my server?:

A couple of other handy links:

• https://mxtoolbox.com/emailhealth
• https://www.warmupinbox.com/

Also this is very interesting, complete and accurate:

• http://multirbl.valli.org/lookup/

[jdaviescoates]

@drpaneas said in gmail blocks my server?:

@jdaviescoates I have cloudron installed at home.

Ah, right.