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 access files.

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.

RELAYCLIENT

Allow the client to relay mail.

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

FAXRELAYCLIENT

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

Note
RELAYCLIENT must also be set. FAXRELAYCLIENT is set in addition to RELAYCLIENT.

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

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:

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

•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.

•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.

@SYSCONFDIR@/SMTPACCESS SUBDIRECTORY¶

The following checks are made on the contents of /etc/courier/smtpaccess:

•Files whose names contain a tilde, “~” are skipped over.

•Files whose names end with the following suffixes result in an error message: “.rpmsave”, “.rpmnew”, and “.dpkg-suffix”. These files are backup files created by package manager when updating to a newer version of the package and contain the old or the new version of a configuration file whose settings may be new or obsolete.

The contents of the file whose name does not have the suffix should be checked against the backup. The backup file should be deleted after making any needed manual changes to the configuration file.

•Files whose names end with the “.dist” suffix is also treated as a configuration file backup or template, but with the following exception: the “.dist” file gets ignored and automatically skipped over, without any error message, if the suffix-less file exists and its modification time is more recent than the “.dist” file's modification time.

Otherwise an error message gets reported. Resolving the error message is done by either copying the “.dist” file or editing and saving the file without the suffix (resulting in a newer timestamp).