Limit Concurrent Connections to a Specific Domain

$domain_limit node @domain [count]

[This command description applies to COPIAFACTS engine release 7.333 and later]

This command is used to limit the e-mail connections to a specific domain from a single CopiaFacts node.  It is provided to help avoid e-mail rejection by remote mail transfer agents (MTAs) which limit connections from a single IP address.

The parameters on this command are used as follows:

nodethe nodename affected, or * for all nodes.
domaina substring of the domain names to which the limit is to be applied, with a leading '@' to ensure that only the domain is checked. For each e-mail address which contains the substring, a separate domain limit of the specified count is established for its domain.
countthe maximum number of allowed connections (default 1)

Multiple commands can be used to specify multiple mail domains to be limited in this way. Including a very large number of commands may affect e-mail throughput.  Domain names are tested in the sequence the commands appear in the file.

When transmissions are inhibited by this command, the FS file involved is written back to the same TOSENDx folder for a later transmission attempt. No attempt record is written, but a variable DOMAINBUSY_COUNT is added to the FS file and incremented each time the FS is deferred for this reason.

You can only determine the need for using this command by analyzing e-mail transmission outcome codes and viewing the CopiaFacts EMAIL_ERROR variable value created during a failed transmission attempt.  Different MTAs may report the rejection with different codes and different messages.

Examples:

Prevent more than two concurrent e-mails being sent to addresses at copia.com:

$domain_limit * @copia.com 2

Prevent more than two concurrent e-mails being sent to addresses at copia.com and more than two concurrent e-mails being sent to addresses at copia.net:

$domain_limit * @copia. 2

Prevent more than three concurrent e-mails being sent to any domain:

$domain_limit * @ 3