[554] Relay access denied

[annami]

Hi...

We are using RHEL v4, we use POSTFIX / Squirrelmail in our mail server. We are able to send / receive all e-mails including external mails when we set incomming / outgoing mail server address using Local IP [192.168.1.101] of the mail server. we tried using MS outlook it works fine.


But we are NOT able to SEND any e-mail to recepients when we configured incomming / outgoing mail server address with the public IP or public host addfress [mailserver.abcd.com] of that server. We are getting Relay Access denied Error..

Since this mail server was configured by another administrator. Kindly let me know that is there nay configurations that prevents relay mail through Public address and allows through ONLY local address of the server for security resons.


Regards
-Annami

[jledhead]

is there nay configurations that prevents relay mail through Public address and allows through ONLY local address of the server for security resons.


Regards
-Annami

yes, and for obvious reasons you wouldn't want everyone in the world to be able to relay to your public ip, that would be bad

what do your postfix logs say and/or whats your postfix main.cf look like?

[salmane]

Hi,

I have the same problem with "Relay access denied" while I m using telnet mysever.com 25 or sending an email by outlook !

PS : all work fine when i'm connected on localhost : i can send end receive my mail.


Regards,
Salmane

[secondmouse]

You can either add the sender's ip to mynetworks setting in main.cf or enable smtpd authentication in postfix.

[salmane]

Thank you secondmouse.

It works when i put mynetworks = the.sen.der.ip,
but the problem is that the user can be anywhere, not only in my local network (LAN) and can have any ip address !

I have also tried :
relayhost=
to tell postfix to relay from all sender !

now everything is allright. i just hope that this second solution doesn't present any security problem, does it ?

Regards,
Salmane

[secondmouse]

I don't know why your setting relayhost to empty allows senders from all IPs to send emails without authentication. According to the postfix doc:

# The relayhost parameter specifies the default host to send mail to
# when no entry is matched in the optional transport(5) table. When
# no relayhost is given, mail is routed directly to the destination.
#
# On an intranet, specify the organizational domain name. If your
# internal DNS uses no MX records, specify the name of the intranet
# gateway host instead.
#
# In the case of SMTP, specify a domain, host, host:port, [host]:port,
# [address] or [address]:port; the form [host] turns off MX lookups.
#
# If you're connected via UUCP, see also the default_transport parameter.
#
#relayhost = $mydomain
#relayhost = [gateway.my.domain]
#relayhost = [mailserver.isp.tld]
#relayhost = uucphost

Adding ips manually to mynetworks setting is quite cumbersome esp. if the sender's ip changes all the time. You best solution is to use smtpd authentication for senders not specified in mynetworks. If you are using dovecot, try this:
Postfix SMTP Authentication and Dovecot SASL | Linux Mail Server Setup and Howto Guide

[salmane]

ok, thank you !

can I user smtpd authentication with LDAP ?

PS : actually I'm using Postfix + Cysurs + Sasl on Ldap