Eric Thomas writes: The only problem is that, roughly speaking, it would add a zero or two to the (machine) costs of running the list. Instead of having to deal with one 2k message going to 100 recipients, the mail system would have 100 2k messages going to 1 recipient each. And that's for a SMALL list. Eric Roger Myers replies: I suppose that you are refering to the fact that messages going to one domain are really sent as a single message with a list of recipiants. For a list having 700 members there is not just 1 message being sent to a list of 700 addresses. It is less efficient then that because not all recipients are at the same domain. But I agree with the general idea which is that it would greatly increase the volume of email (bandwidth) being sent from the LISTSERV site. That is of course only true for the time that the list has the subscription ID feature turned on which could be a very short time automatically controlled. I totally agree that it would not be a good idea to have this feature in effect for a list all the time. The idea though would be for a list owner to be able to turn it on and perhaps it would automatically turn itself off 1. immediately following the distribution of the next posting for all MAIL subscribers. 2. Immediately following the next distribution of the digest and index for all digest and index subscribers. This would allow the list owner to quickly match difficult bounces with a specific subscription while using up a minimum of wasted resources. Another way to implement this feature would be to have it automatically send all subscribers except for NOMAIL subscribers a very tiny note telling them to please ignore this message as it is for tracking down an error with the list. I would prefer the first method because it would not confuse people nearly as much as having them get a message they are told to ignore. But if band width is a major concern then perhaps having a single tiny test message from LISTSERV with the subscriber's ID in the subject line would be ok. do either of these changes make this idea more reasonable? I think the increase when one of the list owners at a site hosting perhaps 150 mailing lists decides to use this feature would hardly be noticed if the feature turns itself off after each non-NOMAIL subscriber has received an individual message from LISTSERV. Let us not forget that many of the list owners out here like myself are managing lists totally as volunteers with regular jobs, families, hobbies and interests other then the lists we manage, etc. Our time and convenience is important to us perhaps at times more important then a small amount of wasted bandwidth. Consider the waste in bandwidth which a mailing list causes as compared to that caused by transfering pictures, motion pictures, etc. on the Internet and keep that also in mind when talking to us about wasted bandwidth. Roger [log in to unmask] - Roger Myers (adoption, aparent, blindfam, and rplist owner)