How to suppress hostname in "telnet <IP> 25"?

[Hai Nguyen_1]

Folks,

I would like to know how to configure sendmail to suppress hostname in the situation below. The command is run in Windows env.

C:\ telnet hp-uxServerIP 25
220 ESMTP
221 hostname.domain closing connection


Connection to host lost.
C:\

How can you suppress "221 hostname.domain closing connection"? Thanks.

Hai

[Sridhar Bhaskarla]

Hi,

Edit /etc/mail/sendmail.cf file and search for "Greeting". Make the line to appear like

O SmtpGreetingMessage=""

-Sri

[Steven E. Protter]

This is probably a sendmail server side configuration issue.

You can quick fix it by changing the Dj parameter in sendmail.cf on the server.

It picks up the hostname if its not set.

You can set it but be careful.

the Dj parameter when set is picked up on outbound mail. If its not fully qualified and can not be resolved aol and other major mail systems will reject the mail.

After making the change:

/sbin/init.d/sendmail stop
/sbin/init.d/sendmail start

Done.

SEP

[Sridhar Bhaskarla]

Hi (again),

Hmmm.. you asked for "closing connection". I don't think you can do it because I believe it isn't really coming from the server side but it's the IP that is getting resolved at the localhost.

-Sri

[Steven E. Protter]

I think you need to check both Sri's suggestion and mine.

It will default to hostname under certain circumstances.

SEP

[Hai Nguyen_1]

Sri,

Thanks for your quick reply. I already have the greeting configured your way which suppresses the hostname info in the initial connection. My question applies to the "closing connection".

Hai

[Hai Nguyen_1]

Sri,

I know for sure the hostname.domain was not resolved at the localhost (client site).

Steve,

Dj is not being used in my sendmail.cf. And I do not need to use it.

All,
Let me try to rephrase my question:

All I need is to suppress hostname.domain in the "221..." line if possible. Thanks again for all your help.

Hai

[Steven E. Protter · Accepted solution]

I have considerable experience with sendmail. If you take Sri's advice(which is good) yo may find the message defaults to the lostname of the system.

The Dj directive lets you overwrite it.

As far as the 221 message goes, thats how sendmail was written. You can take it change the source and recompile it, or use another MTA to change the behavior.

sendmail tells people when it disconnects them. I don't know how to surpress that behavior.

SEP

[Paula J Frazer-Campbell]

Hi

I am not sure but does vrfy off stop this happening or is it just username.



Paula

[Hai Nguyen_1]

Paula,

goaway,noexpn,novrfy have been applied. It is hostname.domain which I like to suppress, not username? By the way, I think Steve is right. There is no way to suppress hostname.domain in "221 hostname.domain closing connection" unless I try another MTA or compile the source code myself. I saw this string "221 %s closing connection" in HP-compiled sendmail.

I close this thread here. Thank you all for your help.

Hai

[Sridhar Bhaskarla]

Hi,

You are right. It does come from the server side. I just ran a tusc on the telnet


socket(AF_INET, SOCK_STREAM, 0) ............................ = 3

send(3, "q u i t \r\n", 6, 0) .............................. = 6
select(2048, 0x40005860, 0x40005760, 0x40005660, 0x40004b48) = 1
recv(3, "2 2 1 hostname.domain ".., 1024, 0) ..... = 48


As indicated by Steven, you can suppress it by manipulating "Dj" macro. But that may open up other problems as you are overwriting the servers' domain.

-Sri