This probably isn't the correct forum to discuss this but from what I can tell Yahoo has recently made changes that are causing all sorts of problems for a lot of people. The following error is received when attempting to connect to the yahoo.com mail servers. 451 Message temporarily deferred - 4.16.50 We have been waiting for a postmaster response to the issue since last week. ~Chris -----Original Message----- From: LISTSERV site administrators' forum [mailto:[log in to unmask]] On Behalf Of Stan Horwitz Sent: Tuesday, October 24, 2006 7:21 AM To: [log in to unmask] Subject: Re: Odd error messages On Oct 24, 2006, at 7:15 AM, Ron wrote: > Hi all, > > I'm getting error messages from legitimate addresses on one of my > lists, which indicates that they are not getting their mail when they > should. They appear to be yahoo addresses. Any ideas? I haven't noticed an unusually high number of bounces from my yahoo subscribers lately. I suggest you try sending one or two of those subscribers a message from your Listserv server, but outside of Listserv to see what the bounced headers look like.