Your isp may be redirecting port 25 bound traffic to it's own servers. Most of the larger ones do this. When I setup a toaster for my last employer, everything worked great inside the office network but when people brought their laptops home a good 75% of them could not send emails. I figured out that their isps were redirecting port 25 traffic. To work around this I just setup another smtpd listener on 2525, configured laptop users email clients smtp port to 2525 and everyone was happy.
-----Original Message----- From: Matthew Walker [mailto:[EMAIL PROTECTED] Sent: Thursday, November 11, 2004 1:43 PM To: [EMAIL PROTECTED] Subject: Re: [toaster] Odd SMTP banner... Ahmet YAZICI said: > Matthew Walker wrote: > >>Relating to the new toaster I set up, I've noticed some odd behavior with >>the banner when you connect to SMTP. Also, commands seem to be somewhat >>limited on remote connections. For example... >> >>Local Test: >> >>[EMAIL PROTECTED] squirrelmail]# telnet localhost 25 >>Trying 127.0.0.1... >>Connected to localhost. >>Escape character is '^]'. >>220 mail.thebraingarden.com ESMTP >>EHLO thebraingarden.com >>250-mail.thebraingarden.com >>250-STARTTLS >>250-PIPELINING >>250-8BITMIME >>250 AUTH LOGIN PLAIN CRAM-MD5 >>MAIL FROM: [EMAIL PROTECTED] >>250 ok >>RCPT TO: [EMAIL PROTECTED] >>250 ok >>QUIT >>221 mail.thebraingarden.com >>Connection closed by foreign host. >> >> >>All very normal, and very well behaved. (And no, it's not an open relay >>unless you're localhost. ;) >> >>Now... Remote Test: >> >>arsenic ~ # telnet mail.thebraingarden.com 25 >>Trying 209.90.91.5... >>Connected to user-5.pl107658.fiber.net. >>Escape character is '^]'. >>220 ***************************** >>EHLO kydance.net >>502 unimplemented (#5.5.1) >>AUTH LOGIN >>502 unimplemented (#5.5.1) >>MAIL FROM: [EMAIL PROTECTED] >>250 ok >>RCPT TO: [EMAIL PROTECTED] >>553 sorry, that domain isn't in my list of allowed rcpthosts (#5.7.1) >>RCPT TO: [EMAIL PROTECTED] >>250 ok >>QUIT >>221 mail.thebraingarden.com >>Connection closed by foreign host. >> >> >>Does this seem odd to anyone else? It behaves /totally/ differently on >> the >>external connection than it does on the internal. >> >> >> > Behind a firewall ? > > The system is behind some kind of NAT setup, but I don't know the precise details. However, I'm fairly certain that it is simply a port-forwarding NAT box, and isn't doing any active firewalling/filtering of the connection. Is there anything else that could cause this? It's not urgent at the moment, but the minute one of the employees tries to send mail from their home computer, it's going to escalate to critical. -- Matthew Walker Kydance Hosting & Consulting http://www.kydance.net
