spam .. open relay from Sendmail 8.8.6 ..

[someone_4]

Hello.
What is the best and most effective way to close open mail relay on Sendmail 8.8.6 ?

Richard

[harry d brown jr]

here is the best doc:

http://www.sendmail.org/antispam.html

live free or die

harry

[Eugen Cocalea]

Hi,

/etc/mail/access

only relay trusted domains.

E.

[Sridhar Bhaskarla]

Richard,

1. Upgrade it to 8.9.x. PHNE_I8546 or later is going to fix it.I have seen some administrators running with 8.9.x version of sendmail configured previous versions of sendmail.cf.

If you are running 8.9.x (what /usr/sbin/sendmail) and if your configuration file is of older version, then you can copy /usr/newconfig/etc/mail/sendmail.cf file into place and duplicate your customizations.
This by default denies relaying.

2. If you don't have 8.9.x and if you don't want to install it now, check out this web site. It gives some macros to disable relay.

http://www.sendmail.org/antirelay.txt


Some information here too

http://www.sendmail.org/m4/anti-spam.html

Check this link on some discussion

http://forums.itrc.hp.com/cm/QuestionAnswer/1,,0xd42f630fe5c4d5118ff10090279cd0f9,00.html


-Sri

[someone_4]

Hi .. I tried to download the newer version of sendmail but here is what I found.
Repost: 01/07/17
A problem has been discovered with superseding patch
PHNE_18546. PHNE_18546 can cause performance issues on systems
with more than 3000 concurrent TCP connections. PHNE_17190
does not exhibit the same behavior, so it is being re-released
until a replacement patch is available.

[Sridhar Bhaskarla]

Ooops.. I forgot to mention. You need to disable identd in /etc/inetd.conf to remedy this patch.

Also edit sendmail.cf file and and make
timeout.ident=0s

and restart sendmail. We did have problems with our network interfaces going crazy. And finally HP came up with this investigation.


-Sri