1) I am blocking sites that:
a) send SPAM to addresses in our domain
b) have broken one of our e-mail passwords and try to send bulk mail
through our server by faking an Artifact Software user.
If postfix or spamassassin detects this behaviour, it blocks it as best
as it can (without making legitimate e-mail hard to send) and creates
log events which fail2ban picks up and blocks the offending IP for a while.
2) We block relaying of mail by unauthenticated users. Any employee who
is not on a local network must use a username and password to send a
mail. Postfix supports this easily and is the way to close an open
relay. I am often out of the office as are most of the employees and
this works fine.
If you are using Postfix, you will find the recipes in "The Book of
Postfix" which is worth buying.
What e-mail client are you using? I use Thunderbird but others use
Outlook and it all works with a simple set up.
I hope that this helps.
Ron
On 23/04/2014 7:43 PM, John Griessen wrote:
On 04/23/2014 04:07 PM, Ron Wheeler wrote:
Another approach to reduce SPAM would be to use fail2ban for a
"reasonable" period to shut out IP addresses for a "reasonable"
period that are sending a "lot" of SPAM in a "short" period.
Hi,
Are you meaning to allow relaying that way, or just for mail that has
a destination
at your server?
I've been trying to figure how to get my mail server to do TLS, but
then found my idea
of do TLS was about sealing off any but a whitelist of senders, and
the list folk think differently,
but then my wife wanted it on a trip, and it became too complicated to
do with my old setup.
So now, I'm planing to switch to dovecot for IMAP mail, and not sure
what security for
on the road uses, and not sure at all what is practical for
smart-phone uses,
and the list folk seem to hate OT anything, and howto a complete
server setup
they definitely put in OT category.
So, if you've found a limiting way that doesn't get you blacklisted,
I'm all ears.
John Griessen
Already blacklisted for no discernible reason by yahoo.com for bounces
from a mailman list
I run...
--
Ron Wheeler
President
Artifact Software Inc
email: rwhee...@artifact-software.com
skype: ronaldmwheeler
phone: 866-970-2435, ext 102
