The reason bulk REGISTER OFF is slow is that LISTSERV aggressively trims the SIGNUP files when records are deleted. The goal is to keep the files small, and under normal conditions there are no bulk de-registrations. You would not normally have a trim more often than once a minute at the most, probably more like once every 5 minutes. Each individual trim is normally a fraction of a second, the problem is when you chain them as fast as possible. The main impact of having too much SIGNUP data is that you waste some disk space (probably not a concern nowadays) and that you need to increase the number of individual files (SIGNUP_HASH) to retain the same level of performance. Other than that, it is no big deal. Very few sites are SIGNUP-constrained. You need an unusual kind of workload to run into that problem. Of course, if you did notice a performance problem with SIGNUP data access, it could make sense to schedule some downtime to deregister the addresses. Eric