topic Re: Relay server in Operating System - HP-UX

Relay server

iman_1 — Mon, 20 Jul 2009 08:33:48 GMT

Is it possible to configure the sendmail without any relay server ?

Example : I have 100 unix host servers, A, B, C, D .......

I want email from A to go directly to B without the need of any relay server ? Although there would be one smtp gateway to send and receive emails from outside for the unix hosts.

Re: Relay server

Michal Kapalka (mikap) — Mon, 20 Jul 2009 08:47:20 GMT

hi,

i think if you make

mailx for examle .... userx@server1(IP)

it should be directly deliver the message.

mikap

Re: Relay server

Ganesan R — Mon, 20 Jul 2009 08:50:18 GMT

Hi,

You don't need any relay server to send mails inside your network. Relay server is to send the mails outside.

Re: Relay server

VK2COT — Mon, 20 Jul 2009 08:54:44 GMT

Hello,

Of course you can configure Mail Transfer Agent
like sendmail not to use relay hosts.

Here is the behaviour when mailertables are
not in use:

a) If sendmail can find MX- resource records
for a specific domain, then it will try
to deliver messages to the servers listed
as MX.

b) If MX- resource records do not exist, than
A- resource records are looked up and
email delivery tried directly.

As long you have a decent host resolution
setup at your company, it will work fine.

Also, the remote servers must listen on,
typically, SMTP port 25. I have seen some
sites using obscure ports for SMTP.
It does not improve security at all but
obviously makes some people happy thinking
that nobody can figure it out :)

To test where email is supposed to be delivered, here is a simple command:

/usr/lib/sendmail -bv user@mydomain.dom

Cheers,

VK2COT

Re: Relay server

Steven E. Protter — Mon, 20 Jul 2009 09:18:32 GMT

Shalom,

Yes you don't need a relay server.

The standard sendmail configuration attempts to resolve the target domain with DNS and get the MX record of the domain and send directly.

Port 25 must be open to the outside world.

The reason most corporate environments use relay servers is because the level of preparation necessary to meet public Internet anti spam rules is onerous.

SEP

Re: Relay server

Vishu — Mon, 20 Jul 2009 18:15:43 GMT

Hi iman,

i hope Ganesan and SEP must have cleared your doubt on relay server that they are used to send mail outside the network, to public internet.

So, you can directly send the mails to other hosts, if they are getting resolved properly.

Thanks