testmxlookup(1) [debian man page]

TESTMXLOOKUP(1) 					      Double Precision, Inc.						   TESTMXLOOKUP(1)

NAME

       testmxlookup - Look up mail relays for a domain

SYNOPSIS

       testmxlookup [@ip-address] [--dnssec] [--udpsize n] {domain}

DESCRIPTION

       testmxlookup lists the names and IP addresses of mail relays that receive mail for the domain. This is useful in diagnosing mail delivery
       problems.

       testmxlookup sends a DNS MX query for the specified domain, followed by A/AAAA queries, if needed.  testmxlookup lists the hostname and the
       IP address of every mail relay, and its MX priority.

   DIAGNOSTICS
       The error message "Hard error" indicates that the domain does not exist, or does not have any mail relays. The error message "Soft error"
       indicates a temporary error condition (usually a network failure of some sorts, or the local DNS server is down).

   OPTIONS
       @ip-address
	   Specify the DNS server's IP address, where to send the DNS query to, overriding the default DNS server addresses read from
	   /etc/resolv.conf.

	   "ip-address" must be a literal, numeric, IP address.

       --dnssec
	   Enable the DNSSEC extension. If the DNS server has DNSSEC enabled, and the specified domain's DNS records are signed, the list of IP
	   addresses is suffixed by "(DNSSEC)", indicating a signed response.

	   This is a diagnostic option. Older DNS servers may respond with an error, to a DNSSEC query.

       --udpsize n
	   Specify that n is the largest UDP packet size that the DNS server may send. This option is only valid together with "--dnssec". If
	   "--dnssec" always returns an error, try "--udpsize 512" (the default setting is 1280 bytes, which is adequate for Ethernet, but other
	   kinds of networks may impose lower limits).

SEE ALSO

       courier(8)[1], RFC 1035[2].

AUTHOR

       Sam Varshavchik
	   Author

NOTES

	1. courier(8)
	   [set $man.base.url.for.relative.links]/courier.html

	2. RFC 1035
	   http://www.rfc-editor.org/rfc/rfc1035.txt

Courier Mail Server						    11/18/2011							   TESTMXLOOKUP(1)

MAKESMTPACCESS, MAKE(8) 				      Double Precision, Inc.					   MAKESMTPACCESS, MAKE(8)

NAME

       makesmtpaccess - Build ESMTP server access file

SYNOPSIS

       makesmtpaccess

       makesmtpaccess-msa

DESCRIPTION

       makesmtpaccess rebuilds the contents of the /etc/courier/smtpaccess.dat database from the contents of the files in the
       /etc/courier/smtpaccess directory. When the esmtpd script starts couriertcpd, the script specifies /etc/courier/smtpaccess.dat file to
       control access to the Courier mail server's ESMTP daemon. The makesmtpaccess script must be run before any changes in the
       /etc/courier/smtpaccess directory take effect.

       The couriertcpd(8)[1] manual page describes the general format of the access file.

       The default Courier mail server configuration uses the same access file, /etc/courier/smtpaccess.dat for both the regular ESMTP server, and
       the message submission server on port 587 (RFC 2476[2]). It is possible to use different access files. To do so, create a different access
       file, edit /etc/courier/esmtpd-msa, and set ACCESSFILE to the filename of the access file directory (the directory containing the plain
       text files, not the .dat file). Then, use makesmtpaccess-msa instead of makesmtpaccess to build the .dat file.

   The smtpaccess configuration file
       The couriertcpd(8)[1] manual page describes the generic format of the access file. The access file specifies what should be done with
       connections from defined IP address ranges. The basic choices are to accept or reject the connection. Also, the generic format of the
       access file allows arbitrary environment variables to be set based on the connection's remote IP address.

       The Courier mail server's ESMTPD server understands the following environment variables, which may be set in the access file:

       BLOCK
	   If this variable is set to a non-empty value, all mail will be rejected for this connection. The contents of the environment variable
	   will be used as the error message. This is not the same as the couriertcpd access file setting that immediately drops the connection.
	   The incoming connection is accepted, but every message will be rejected.

       FAXRELAYCLIENT
	   Allow the client to send faxes via the courierfax(8)[3] module.

	       Note
	       When ESMTP authentication is enabled, a successful authentication automatically sets FAXRELAYCLIENT.

       RELAYCLIENT
	   Allow the client to relay mail.

	       Note
	       When ESMTP authentication is enabled, a successful authentication automatically sets RELAYCLIENT.

       The following options are typically set globally in the esmtpd configuration file, but may be overriden in the smtpaccess configuration
       file:

       BOFHCHECKDNS
	   Do not check the return address's domain in DNS if this environment variable is set to 0. The default value of BOFHCHECKDNS is 1.

	       Note
	       Turning off the DNS check disables a number of options in the bofh configuration file. See courier(8)[4] for more information.

       BOFHCHECKHELO
	   Set this variable to 1 to check the hostname argument to the ESMTP HELO/EHLO command, as follows:

	   o   A hostname that's actually an IP address, and is the same as the connecting ESMTP client's IP address, is valid.

	   o   Otherwise hostname should be a valid DNS name with MX and/or A records, with at least one record matching the connecting ESMTP
	       client's IP address.

	   o   An ESMTP client with relaying privileges (either due to RELAYCLIENT explicitly set, or if it succesfully authenticates) may use
	       anything for an EHLO/HELO. The EHLO/HELO argument coming from an authenticated/relaying client is not checked.

       BOFHNOEXPN
	   Disable the EXPN command if this environment variable is set to 1.

       BOFHNOVRFY
	   Disable the VRFY command if this environment variable is set to 1.

       Other useful environment variables are listed in the submit(8)[5] manual page.

SEE ALSO

       esmtpd(8)[6], couriertcpd(8)[1], submit(8)[5].

AUTHOR

       Sam Varshavchik
	   Author

NOTES

	1. couriertcpd(8)
	   [set $man.base.url.for.relative.links]/couriertcpd.html

	2. RFC 2476
	   http://www.rfc-editor.org/rfc/rfc2476.txt

	3. courierfax(8)
	   [set $man.base.url.for.relative.links]/courierfax.html

	4. courier(8)
	   [set $man.base.url.for.relative.links]/courier.html

	5. submit(8)
	   [set $man.base.url.for.relative.links]/submit.html

	6. esmtpd(8)
	   [set $man.base.url.for.relative.links]/esmtpd.html

Courier Mail Server						    08/30/2011						   MAKESMTPACCESS, MAKE(8)