Maxconnectionsperdomain smartsend Channel Option

Maximum number of connections from an IP to a domain
The  smartsend channel option implements limits on the number of simultaneous connections that can be opened to a destination domain. The value of this parameter is one or two space-separated limit lists. The first value specifies the limits to use when the IP address is operating normally; the second specifies the limits to use when operating in IP backoff mode. If the IP backoff value is omitted it defaults to the first value.

Note that the identically named  smartsend  parameter provides the same functionality at the domain or IP level.

This option requires that the smartsend callouts, in particular the callouts from the  and   mappings, be installed. This option will be ignored if smartsend is not configured.

See also:
 * smartsend callouts