HowtoForge Forums | HowtoForge - Linux Howtos and Tutorials

HowtoForge Forums | HowtoForge - Linux Howtos and Tutorials (http://www.howtoforge.com/forums/index.php)

- Installation/Configuration (http://www.howtoforge.com/forums/forumdisplay.php?f=16)

- - Mail server host name in greeting (http://www.howtoforge.com/forums/showthread.php?t=12650)

Mail server host name in greeting

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

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.

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!

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

Code:

hostname -f

?

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

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 It's outdated, but there's no new standard, let alone a good solution.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

Thanks Falko, here is main.cf:

Code:

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!

Quote:

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.

Quote:

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.

I see - well I guess it was rather simple then!

Thanks again for the help, it seems to be passing the tests now. I was worried that the name had to match up with its respective domain - good to know that it does not.

Sorry to reopen such an old thread but I have the same problem:

the check: Check SMTP Greeting
the result: WARNING: The following mailservers don't have their host name in greetings:
mail.sa-tax.co.za → h1870666.stratoserver.net

so what is wrong with my mail server not having its host name in greetings?
would you mind checking this from another machine please?

Sorry, I decommissioned my server several years ago so I have no way to re-test. I was however able to resolve the issue following the advice given above. Good luck.