Our dedicated server host (BodHost) changed the IP addresses for the windows 2003 server on which we have LISTSERV 1.8e installed. LISTSERV is configured to use a mail server (IMail 2006) installed on another machine, hosted by a different server host (Rackspace), as its SMTP server. This setup has been working perfectly for more than two years. These are some of the pertinent site.cfg settings: SMTP_Forward: server1.whathelps.com SMTP_Forward_n: server1.whathelps.com (Host name of the mail server machine. Nothing with this machine or the DNS/IP of server1.whathelps.com has changed. Node: LISTSERV.NETHELPS.COM I made the IP changes in the DNS for listserv.nethelps.com and all domains/subdomains LISTSERV is configured to use. I've done traces for listserv.nethelps.com and archives.nethelps.com (LISTSERV archives) and both resolve correctly to the new IP, 174.141.229.14. However, I cannot access the web interface or archives. (See http://listserv.nethelps.com/wa.exe and http://archives.nethelps.com/wunrn_listserve.html.) However, I can access the archives for that list if I use the customer's subdomain. (See http://lists.wunrn.com/wunrn_listserve.html.) That makes no sense, because lists.wunrn.com is configured in IIS as an alias of archives.nethelps.com and both use the same IP, 174.141.229.14. I made the same IP changes in IIS on the LISTSERV machine. I added the new IP on the mail server firewall. I made the IP changes in the mail server's SMTP settings (it is configured to relay for addresses). I restarted LISTSERV, LISTSERV smtp listener, and the mail server's services. In reviewing the mail server's SMTP logs, the mail server (at 64.49.220.152) first connected with LISTSERV at 1:09am and continued to do so until 2:15am. At 2:15am, LISTSERV begins reporting the connection error. --> 05:20 01:09 SMTPD(d223024f00002c3f) [64.49.220.152] connect 174.141.229.14 port 4059 20 May 2010 02:15:04 >>> Error 11004 resolving SMTP host 'SERVER1.WHATHELPS.COM', will try again in 1 minute <<< At the time LISTSERV stopped connecting to the mail server, I was finishing up all the IIS changes and the changes to IMail. I restarted LISTSERV at 2:14:44, which seems to be what immediately preempted the connection problem. --> 20 May 2010 02:14:44 >>> Service termination request received, shutting down. 20 May 2010 02:14:44 From [log in to unmask]: STOP * There are 11 jobs still to be processed and 11 held jobs waiting to be * released. The average CPU time used by LISTSERV for this session is 0.1%. * Since LISTSERV was last rebooted (on 19 May 2010 at 23:46, ie 2h28 ago), the * following requests have been processed: * * - Interactive messages from users 26 * - Postings to distribution lists 4 (1470 recipients) * - DISTRIBUTE jobs (internal) 49 * - DISTRIBUTE jobs (from network) None * - Other incoming files 89 * * - Database searches (interactive) None * - Database searches (batch mode) None * 20 May 2010 02:14:44 Waiting for SMTP workers to terminate... 20 May 2010 02:14:44 -> All workers have exited. 20 May 2010 02:14:52 LISTSERV(R) for Windows NT version 1.8e starting... 20 May 2010 02:14:52 Copyright L-Soft international 1986-2002 20 May 2010 02:14:52 Requeuing 4 mail files for delivery... 20 May 2010 02:14:52 SIGNUP files are being compressed... 20 May 2010 02:14:52 -> No entry removed. 20 May 2010 02:14:52 The network tables are outdated and must be rebuilt. 20 May 2010 02:14:52 Building list indexes... 20 May 2010 02:14:52 License activated: SERIAL=WHATHELPS-2, UNITS=0