Deliver list mail to each member individually
If selected, when messages are received for distribution to the list, a separate copy of each message will be created and dispatched to each list member. This will result in numerous individual messages being created which could affect the server's performance, depending on the size of the list and the load on the server.
Replace Message-ID with unique value for each member
When MDaemon is set to generate a separate copy of each message for each member, click this checkbox if wish each of those messages to have a unique Message-ID.
Deliver list mail using individual RCPT commands for each member
If selected, MDaemon will route a single copy of each list message to the specified smart host, rather then send individual messages to each member. This method employs multiple RCPT To statements during the SMTP session with the specified host.
Deliver to this host
Designate the smart host to which you wish to pass all of the list's messages for delivery, using RCPT To statements for each member.
Limit RCPTs to [xx] per message (0=no limit)
Some hosts limit the number of RCPT To statements that they will accept when you are attempting to route a single copy of a message through them. If you specify the limit in this control then MDaemon will work around it by creating additional copies of the message and dividing the list into smaller groups. Then it will deliver the message to those groups thus avoiding the need to exceed the limitation. This is similar to the Deliver list mail to each member individually option above, but it generates less copies, sending each copy to groups of addresses rather than generating a separate copy for each member.
Ignore RCPT errors when sending to host
Since some smart hosts will refuse to queue or spool mail for certain domains, the routed approach to list delivery could cause numerous problems. An error code returned from the smart host as a result of this refusal would ordinarily cause MDaemon to abort the delivery attempt. Check this option if you want MDaemon to ignore error codes returned from the smart host during delivery of routed list mail, thus allowing those members that are accepted a chance to receive the message.