3

I've been trying to set up a mail server with postfix. Sending/receiving local mail and receiving external mail works. However, sending external mail does not work.

When I start sending a message through telnet example.com 25 I get the following message after typing rcpt to: [email protected]:

454 4.7.1 < [email protected]>: Relay access denied

Some information that might be helpful:

/etc/postfix/main.cf

# See /usr/share/postfix/main.cf.dist for a commented, more complete version
# Debian specific:  Specifying a file name will cause the first
# line of that file to be used as the name.  The Debian default
# is /etc/mailname.
#myorigin = /etc/mailname

smtpd_banner = $myhostname ESMTP $mail_name (Ubuntu)
biff = no

# appending .domain is the MUA's job.
append_dot_mydomain = no

# Uncomment the next line to generate "delayed mail" warnings
#delay_warning_time = 4h

readme_directory = no

# TLS parameters
smtpd_tls_cert_file=/etc/ssl/certs/ssl-cert-snakeoil.pem
smtpd_tls_key_file=/etc/ssl/private/ssl-cert-snakeoil.key
smtpd_use_tls=yes
smtpd_tls_session_cache_database = btree:${data_directory}/smtpd_scache
smtp_tls_session_cache_database = btree:${data_directory}/smtp_scache

# See /usr/share/doc/postfix/TLS_README.gz in the postfix-doc package for
# information on enabling SSL in the smtp client.

smtpd_relay_restrictions = permit_mynetworks permit_sasl_authenticated defer_unauth_destination
myhostname = example.com
virtual_alias_maps = hash:/etc/postfix/virtual
alias_database = hash:/etc/aliases
myorigin = /etc/mailname
mydestination = example.com, mycomputername, localhost.localdomain, localhost
relayhost = mail.example.com
mynetworks = 127.0.0.0/8 [::ffff:127.0.0.0]/104 [::1]/128 192.168.0.0/24
mailbox_size_limit = 0
recipient_delimiter = +
inet_interfaces = all
inet_protocols = all 
1
  • I emptied the relayhost parameter because the postfix manual mentions that this will deliver directly to the internet. I'm still getting the same relay access denied error though when using telnet. When using the mail command, I read in the mail log the following: status=bounced ... host said: 550-Verification failed for user@mycomputername. Why does postfix use my computer name?
    – Chris
    Aug 18, 2015 at 13:00

1 Answer 1

1

As it turns out. My internet service provider (ISP) blocks outgoing mail. They however provided a relay option: smtp.myisp.tld. I had to use this address as my relay host in the /etc/postfix/main.cf config file:

relayhost = smtp.myisp.tld

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .