When sending a mail...

[Jonathan Caplette_1]

Hi guys...

I wanna know when I'm sending a mail from a machine to someone, where does it chose the server to send it....

I explain...

My domain name is subdomain1.domain1.com and I'm sending a mail to test@hotmail.com , I use a DNS without MX entry, when I check the log file I see that the mail has been intercept by the smtp server of hotmail, what I wanna know is how it determinat that @hotmail.com is to go on that smtp server...

thanks!
jonathan

[benoit Bruckert]

Hi,
What you mean by DNS without MX is the server side, but you should have the root servers defined ..
And in such case, it's possible to find @hotmail.com (you become a client).
Just make this test from the command line :
nslookup www.hotmail.com
If you have the answer, then you dns server is also a caching server, and then you can ask for any MX on internet....
If it doesn't work, then may be you are using a relay ?

hope that help
Benoit

[Jonathan Caplette_1]

OK it anwser me, when I'm doing a nslookup www.hotmail.com

but what I mean is that:

I used to have an MX entry on my DNS server, the thing is that I was able to send mail to any other smtp on the internet and some of our company I timeout with them... So I decided to remove the MX entry in my DNS and test it like that I always timeout with the server of our company... But I know that I have a forward entry on my DNS... I think they take the smtp from another DNS in our company... But even if I use any internet smtp server, I timeout with another server that is not even in my DNS... that's my real problem... I wanna send mail via a local smtp server....

[Balaji N]

Hi,

try sendmail -bv .

From the manpage of sendmail.

G??bv Verify names only G?? do not try to collect or deliver a message. Verify mode is normally used for validating users or mailing lists.

hth
-balaji

[Jonathan Caplette_1]

I wanna know how do it define that @hotmail.com must go on mx4.hotmail.com ... is it broadcasting on the internet???

[W.C. Epperson]

Hotmail has four equally "preferred" MX servers, as shown by the DNS query below. To understand how MX records are used in SMTP, see RFC2821.
#dig hotmail.com mx
; <<>> DiG 9.2.1 <<>> hotmail.com mx
;; global options: printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 51502
;; flags: qr rd ra; QUERY: 1, ANSWER: 4, AUTHORITY: 4, ADDITIONAL: 8

;; QUESTION SECTION:
;hotmail.com. IN MX

;; ANSWER SECTION:
hotmail.com. 383 IN MX 5 mx1.hotmail.com.
hotmail.com. 383 IN MX 5 mx2.hotmail.com.
hotmail.com. 383 IN MX 5 mx3.hotmail.com.
hotmail.com. 383 IN MX 5 mx4.hotmail.com.

[Arnold Hausmann · Accepted solution]

If I understand you correctly, what you're looking for is the DS entry in the sendmail.cf file (should be /etc/mail/sendmail.cf).

The tech notes inside sendmail.cf state "Relay all non-local mail to the "Smart" relay host (DS) via smtp:". On all my servers, this is set to the /etc/hosts alias of my networks SMTP server (unfortunately, MS Exchange--so yes, I have to use LookOut 97, etc.)

You could update the sendmail.cf entry and restart sendmail to change local SMTP servers.