Mail server host name in greeting

[wrender]

I have recently done a dnsstuff.com test on my ispconfig server, and it reports everything back that I expected, except for one warning... It's reporting...
"Mail server host name in greeting"
My domain is otherdata.com, otherdatanetworks.com

I could have swore that the last time I ran dns tests, I did not get this warning. Is it possible for something to have changed for postfix on my server?

Thank you

[till]

Have a look at your postfix main.cf file, if it contains the correct domain. Also check /etc/mailname, if you use ubuntu or debian.

[Ashaman074]

I have this same thing happening; how does this work when hosting more than one domain?

For example, right now I have 123.com and abc.com.

If I run a check on abc.com, it might come back saying "WARNING: One or more of your mailservers is claiming to be a host other than what it really is...mail.abc.com claims to be non-existent host GW.123.com: 220 GW.123.com ESMTP Postfix (Ubuntu)"

/etc/mailname says it is GW.123.com.

Is the problem that it is "claiming" to be GW.123.com or is it that GW.123.com doesn't have a DNS entry? (Or both??)

I don't understand how having more than one domain affects this.

Thanks!

[falko]

What's in /etc/postfix/main.cf (please strip out the comments), and what's the output of

hostname -f

?

Have you tried to put mail.abc.com into /etc/mailname?

[tebokkel]

The name your server uses for the HELO should preferably be an existing hostname (in DNS that is), with the reverse DNS for that IP being the same name. However, although it has become more customary to check for this relation and refuse mail if:
- you don't send a fully qualified name (missing dots)
- you send their own hostname(s) or their IP
- you send "localhost"
and of course:
- if your greeting doesn't match DNS and/or reverse IP.

A setup-checker (as you probably used) can detect all of this, but it doesn't really matter. Most sites hapily accept all kinds of BS, as http://www.faqs.org/rfcs/rfc2505.html makes these checks optional (MAY) or doesn't mention them. Rfc2505 mostly caused open relays to vanish. It's outdated, but there's no new standard, let alone a good solution.


Bottomline: try go get /etc/mailname in line with a forward DNS name and preferably with your reverse DNS too. If not, at least change mailname to your current DNS name.

Paul

[Ashaman074]

Thanks Falko, here is main.cf:

smtpd_banner = $myhostname ESMTP $mail_name (Ubuntu)
biff = no
append_dot_mydomain = no
smtpd_tls_cert_file = /etc/postfix/ssl/smtpd.crt
smtpd_tls_key_file = /etc/postfix/ssl/smtpd.key
smtpd_use_tls = yes
smtpd_tls_session_cache_database = btree:${queue_directory}/smtpd_scache
smtp_tls_session_cache_database = btree:${queue_directory}/smtp_scache
alias_maps = hash:/etc/aliases
alias_database = hash:/etc/aliases
myorigin = /etc/mailname
mynetworks = 127.0.0.0/8
mailbox_size_limit = 0
recipient_delimiter = +
mailbox_command = procmail -a "$EXTENSION"
inet_protocols = all
smtpd_sasl_local_domain = 
smtpd_sasl_auth_enable = yes
smtpd_sasl_security_options = noanonymous
broken_sasl_auth_clients = yes
smtpd_recipient_restrictions = permit_sasl_authenticated,permit_mynetworks,reject_unauth_destination
smtpd_tls_auth_only = no
smtp_use_tls = yes
smtp_tls_note_starttls_offer = yes
smtpd_tls_CAfile = /etc/postfix/ssl/cacert.pem
smtpd_tls_loglevel = 1
smtpd_tls_received_header = yes
smtpd_tls_session_cache_timeout = 3600s
tls_random_source = dev:/dev/urandom
virtual_maps = hash:/etc/postfix/virtusertable
mydestination = /etc/postfix/local-host-names

Hostname -f outputs - GW.123.com

/etc/mailname also lists GW.123.com

Tebokkel, are you saying the name doesn't really matter, so long as it is a valid name that exists in DNS? So for example, if i am sending from abc.com it is OK if it identifies itself as GW.123.com so long as GW.123.com resolves to the correct IP?

So based on the input, maybe I should just change /etc/mailname to something that resolves or create a record for GW.123.com?

Thanks for your help with this!

[till]

Tebokkel, are you saying the name doesn't really matter, so long as it is a valid name that exists in DNS? So for example, if i am sending from abc.com it is OK if it identifies itself as GW.123.com so long as GW.123.com resolves to the correct IP?

yes.

So based on the input, maybe I should just change /etc/mailname to something that resolves or create a record for GW.123.com?

yes.