Topic: SMTP EHLO on port 465

[edb]

I was wondering if anyone knows why I can get a smtp EHLO response no problem when I use the standard SMTP  port 25 but when I use port 465 I get no response at all.
What must I do to get port 465 to respond to the EHLO command with the standard "HI pc-xxxx.mydomain.com"?
A fax server that we are setting up in a remote office requires a reply to the EHLO request or it just won't work.
Since this is a remote office it requires secure port 465 in order to send mail through our server.

I could use the ISP's SMTP server for this purpose however I just wanted to know if there was something simple that could be done on the SME server to allow the EHLO reply.

Thanks

edb

[CharlieBrady]

I was wondering if anyone knows why I can get a smtp EHLO response no problem when I use the standard SMTP  port 25 but when I use port 465 I get no response at all.

I know.

What must I do to get port 465 to respond to the EHLO command with the standard "HI pc-xxxx.mydomain.com"?

You must 'talk' SSL - however, I've never heard of anyone being able to type correct SSL negotation and encryption via telnet.

[edb]

Thanks Charlie ... guess that says it all.
Feel kind of dumb for asking now ... SSL would certainly explain it.

My server is set up to only accept SSL port 465 which is the safest but is this RFC compliant?

[CharlieBrady]

My server is set up to only accept SSL port 465 which is the safest but is this RFC compliant?

Does this answer your question?

Code: [Select]

grep '465/tcp' /etc/services

The 'smtps' entry in /etc/services is ubiquitous, and was originally specified in http://www.iana.org/assignments/port-numbers. You will notice there now, however, that port 465 has been re-assigned to 'urd':

urd             465/tcp    URL Rendesvous Directory for SSM

You can read some background at http://www.rickk.com/sslwrap/

So, in summary, port 465 has never been RFC specified, but the port was assigned for the SSL wrapped SMTP service by IANA (following the recommendation of the Netscape SSL v3.0 draft date back in 1996), but no longer is assigned to that service. Port 465 for SSL wrapped SMTP is still a very widely deployed convention.

Here's some more background:

http://www.irbs.net/internet/postfix/0710/0880.html

P.S. You owe me a few beers for doing your research for you.

[edb]

Wow, thanks for all the info Charlie!
Should I FedX that beer or just have one for you and tell you how good it was?

Thanks very much again, you're a champ.

Edb