In article <8EE11B75E1F8A7E7105A1573@PSB> you write: >It has recently come to the attention of several of us, via an >extended discussion on the SMTP list, that the IETF email >servers are rejecting all SMTP connections whose EHLO commands >contain IP address literals. ... $ telnet -4 mail.ietf.org 25 Trying 4.31.198.44... Connected to mail.ietf.org. Escape character is '^]'. 220 ietfa.amsl.com ESMTP ehlo [64.57.183.53] 250-ietfa.amsl.com 250-PIPELINING 250-SIZE 67108864 250-ETRN 250-STARTTLS 250-AUTH PLAIN LOGIN 250-AUTH=PLAIN LOGIN 250-ENHANCEDSTATUSCODES 250 8BITMIME quit 221 2.0.0 Bye Connection closed by foreign host. $ telnet mail.ietf.org 25 Trying 2001:1900:3001:11::2c... Connected to mail.ietf.org. Escape character is '^]'. 220 ietfa.amsl.com ESMTP ehlo [ipv6:2001:470:1f07:1126:0:43:6f73:7461] 250-ietfa.amsl.com 250-PIPELINING 250-SIZE 67108864 250-ETRN 250-STARTTLS 250-AUTH PLAIN LOGIN 250-AUTH=PLAIN LOGIN 250-ENHANCEDSTATUSCODES 250 8BITMIME quit 221 2.0.0 Bye Connection closed by foreign host.