Debian – Some mail providers reject the mails

debianemail-serverpostfix

I recently moved to a new server and now one of my users complain about e-mails which don't reach the recipient. The mail logs tell me that they reject the mail

AOL will not accept delivery of this message. (in reply to end of DATA command))

refused to talk to me: 421 mtaig-mba02.mx.aol.com Service unavailable - try again later

Recipient address rejected: aol.com (in reply to RCPT TO command))

and finally

(host mailin-03.mx.aol.com[64.12.91.196] said: 521 5.2.1 :  (CON:B1)  http://postmaster.info.aol.com/errors/554conb1.html (in reply to end of DATA command))

Now I'm unsure, if I have some problems with my postfix configuration or if my hoster assign me an old IP Address with "bad reputation" and it isn't really my fault.

This is what my current main.cf looks like

smtpd_banner = $myhostname ESMTP $mail_name (Debian/GNU)
biff = no

append_dot_mydomain = no

readme_directory = no

smtpd_tls_cert_file = /root/ssl/startssl/domain_with_chain.pem
smtpd_tls_CAfile = /root/ssl/startssl/ca.pem
smtpd_tls_key_file = /root/ssl/domain.key

smtpd_use_tls=yes
smtpd_tls_received_header = yes
smtpd_tls_session_cache_database = btree:${data_directory}/smtpd_scache
smtp_tls_session_cache_database = btree:${data_directory}/smtp_scache

smtpd_tls_session_cache_timeout = 3600s
smtpd_tls_loglevel = 3
tls_random_source = dev:/dev/urandom


myhostname = domain.de
mydestination = localhost, localhost.localdomain
alias_maps = hash:/etc/aliases
alias_database = hash:/etc/aliases
myorigin = /etc/mailname
relayhost = 
mynetworks = 127.0.0.0/8 [::ffff:127.0.0.0]/104 [::1]/128
mailbox_size_limit = 0
recipient_delimiter = +
inet_interfaces = all

smtpd_relay_restrictions = permit_mynetworks permit_sasl_authenticated defer_unauth_destination
smtpd_recipient_restrictions = permit_mynetworks, permit_sasl_authenticated, reject_unauth_destination
smtpd_sasl_authenticated_header = yes
smtpd_sasl_auth_enable = yes
broken_sasl_auth_clients = yes

virtual_alias_domains =
virtual_alias_maps = proxy:mysql:/etc/postfix/mysql-virtual_forwardings.cf, mysql:/etc/postfix/mysql-virtual_email2email.cf
virtual_mailbox_domains = proxy:mysql:/etc/postfix/mysql-virtual_domains.cf
virtual_mailbox_maps = proxy:mysql:/etc/postfix/mysql-virtual_mailboxes.cf
virtual_mailbox_base = /home/vmail
virtual_uid_maps = static:5000
virtual_gid_maps = static:5000
transport_maps = proxy:mysql:/etc/postfix/mysql-virtual_transports.cf

proxy_read_maps = $local_recipient_maps $mydestination $virtual_alias_maps $virtual_alias_domains $virtual_mailbox_maps $virtual_mailbox_domains $relay_recipient_maps $relay_domains $canonical_maps $sender_canonical_maps $recipient_canonical_maps $relocated_maps $transport_maps $mynetworks $virtual_mailbox_limit_maps

content_filter = amavis:[127.0.0.1]:10024
receive_override_options = no_address_mappings

Any suggestions for improvements or ideas what went wrong?

Best Answer

The error message from AOL seems to indicate that indeed your IP address was blocked.

You could try to check using online databases such as senderbase if your IP has a listed reputation.

Unfortunatly, it is the nature of banning that you cannot do much more to resolve it than to try to appeal to the relevant provider (in this case, AOL) and explain that this IP has changed hands since they banned it.

As a dirty quick fix, if you have another server, you can also use it to selectively relay mails intended to AOL so that it doesn't appear to originate from the banned server.