Configurar un PTR reverso para evitar bloqueo de correos

Hola,

Hoy me ha comentado @alterannda que algunos de los correos que está mandando están siendo rechazados. Hay que decir que ella usa un dominio personal que hemos configurado recientemente y reportado aquí.

En concreto me ha llamado la atención el siguiente error:

He ido al enlace y he traducido del alemán:

554 Nemesis ESMTP Service not available No SMTP service Bad DNS PTR resource record.

Caused

Emails from your email server have been rejected because the PTR Resource Record (PTR-RR) of your IP address does not meet our policies.

Solution

Make sure that you are not using a dynamically assigned IP address, but rather one that is permanently assigned to your email server.

The PTR-RR should not correspond to the generic standard entry of your host/provider, e.g. “123-123-123-123-static.yourprovider.tld”.
Generic standard entries usually result in rejection.

Assign your email server its own full domain name (FQDN), e.g. according to the recommended format:
“mail.yourdomain.tld”

En la documentación de iredmail (el software que usamos para el correo) pone:

Why do you need a reverse PTR record

The most common use for looking up a PTR record is done by spam filters. Concept behind this idea is that fly by night spammers who send e-mails out using fake domains generally will not have the appropriate reverse PTR setup at the ISP DNS zone. This criterion is used by spam filters to detect spam. If your domain does not have an appropriate reverse PTR record setup then chances are email spam filtering software MIGHT block e-mails from your mail server.

How to setup a Reverse PTR record

You would most likely need to contact your ISP and make a request to create a reverse PTR record for your mail server IP address. For example, if your mail server hostname is mail.mydomain.com then ask your ISP to setup a reverse PTR record 192.168.1.5 (your internet public IP address) in their reverse DNS zone. Reverse DNS zones are handled by your ISP even though you may have your own forward lookup DNS zone that you manage.

En nuestro caso creo que se puede configurar en Hetzner, dónde tenemos el servidor y se nos ha asignado la IP.

He ido al panel de Hetzner y he cambiado el parámetro Reverse DNS entry de la configuración IP del servidor.

He cambiado “static.157.21.216.95.clients.your-server.de” por “anartist.org”.

Esperemos que sirva para no ser rechazados!

3 Me gusta

Brutal, gràcies!

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MArcel moltes i moltes gràcies, us mantinc updated!!!

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