The best value for "Loopcheck=" is no value, ie edit the list header and remove the string "Loopcheck= Nobody". Any other value apart from "Full", which is the default, means that some or all of the loop checking routines are disabled. "Nobody" means that LISTSERV is not allowed to look into the message body to decide whether or not something is a delivery error; it is to rely solely on the 'Subject:' field. As you can imagine, this is a very dangerous option: it means that any mailer not using one of the "standard" subjects known to LISTSERV will cause a loop. "None" is even worse, it tells LISTSERV that, by definition, anything that reaches its reader is NOT a delivery error. These two options should never be used unless the list is moderated. Even if the list is moderated they are not recommended, especially if the moderator is not the list owner (ie administrator). I actually regret having implemented these options, it really scares me to think that people are using them without knowing what they do. "Notocount" means that LISTSERV should not count the 'To:' fields in the message body and decide it is seeing a delivery notice if there are too many; "MaxTo(nnn)" orders it to allow up to the specified amount of 'To:' fields, the default is 10. This is the one sub-option of the "Loopcheck" keyword that can be useful - for digests. The code that counts the 'To:' field is here as a kind of "last resort" action anyway, to prevent infinite loops, but it won't stop the redistribution of the first 'nnn' nastygrams. If you disable this routine it means loops can become infinite, but it doesn't have any effect on the actual detection of new loops. Finally, the latest addition, "NoCRC", means you don't want to suppress duplicate messages on the list, ie if RSCS at FOO becomes crazy and sends you 200 copies of the same posting, as it happened for LSTSRV-L, INFO-VAX and many other lists about 6 weeks ago, you will happily redistribute the 200 copies. I added this option as a kind of "emergency bypass" in case the new code that detects such duplicates should break and start rejecting all postings. Fortunately this did not happen, so you can forget about it. Eric