Cuando terminamos de configurar un servidor en linux, es frecuente encontrarse con el siguiente error.
Comando:
sudo sendmail -v -Am -i [email protected]
Salida comando:
myname@fx1:/etc/mail$ sudo sendmail -v -Am -i [email protected];
[email protected]… Connecting to aspmx.l.google.com. via esmtp…
220 mx.google.com ESMTP v1si55415385wja.21 – gsmtp
EHLO staging.mydomain.com
250-mx.google.com at your service, [2a01:4f8:212:27c8::2]
250-SIZE 35882577
250-8BITMIME
250-STARTTLS
250-ENHANCEDSTATUSCODES
250-PIPELINING
250-CHUNKING
250 SMTPUTF8
STARTTLS
220 2.0.0 Ready to start TLS
EHLO staging.mydomain.com
250-mx.google.com at your service, [2a01:4f8:212:27c8::2]
250-SIZE 35882577
250-8BITMIME
250-ENHANCEDSTATUSCODES
250-PIPELINING
250-CHUNKING
250 SMTPUTF8
MAIL From:[email protected]
250 2.1.0 OK v1si55415385wja.21 - gsmtp
RCPT To:[email protected]
DATA
250 2.1.5 OK v1si55415385wja.21 - gsmtp
354 Go ahead v1si55415385wja.21 - gsmtp
.
550-5.7.1 [2a01:4f8:212:27c8::2] Our system has detected that this message does
550-5.7.1 not meet IPv6 sending guidelines regarding PTR records and
550-5.7.1 authentication. Please review
550-5.7.1 https://support.google.com/mail/?p=ipv6_authentication_error for more
550 5.7.1 information. v1si55415385wja.21 - gsmtp
myname… Connecting to local…
myname… Sent
Solución
Entrar en el fichero de configuración /etc/postfix/main.cf
Cambiar inet_protocols = all por inet_protocols = ipv4
Reiniciar el servicio con el siguiente comando:
service postfix restart
Comprobar cambios
Comando:
postconf inet_protocols
Salida comando:
inet_protocols = ipv4


