PHWinfo - Afficher un message - Stop sending bounce back message with user unknown

30/10/2006, 13h42

Kari Hurtta wrote:
> "Simon" <Simon.SM.Li@gmail.com> writes:
>
>> Hi,
>>
>> I would like to know is it possible to configure in Sendmail to disable
>> the bounce back message to sender if the recipient is unknown "550
>> 5.1.1 <recipient_address>... User unknown". Thanks.
>
> None.
>
> Generally bad idea. Will cause that mails to mistyped addresses go to
> black hole.
>
> Perhaps you should look problem from different light ?
>
> / Kari Hurtta
I have the same problem. I receive over 1000 messages a day to
randomnames@mydomain.com. This number is growing weekly (I track them
before the logs get rotated). I've gone from a few hundred a week to
over 20,000 a week. On an impulse I wrote a script to look at the last
1000 lines in /var/log/maillog every 5 minutes and find any occurrenct
of "... User unknown".

> Oct 30 08:28:13 lazarus sendmail[6422]: k9UDSDd06422: <caninecommendatory@mydomain.com>... User unknown
> Oct 30 08:28:13 lazarus sendmail[6422]: k9UDSDd06422: from=<>, size=0, class=0, nrcpts=0, proto=SMTP, daemon=MTA, relay=sv203.lolipop.jp [202.181.96.40]

Since (on my server) the next line usually contains the sending party's
information, I pull the FQDN, IP Address, bogus email address (from
prior line) and the timestamp from the bounce. As there can be numerous
"User unknown" messages from that address I write the all to a MySQL
database then add new ones to a table which has a unique index defined
on the IP address. I take the IP Address from the unique table and add
it to IPTables blocking everything from that source.

I wanted to do this on another server I support but after looking at
/var/log/maillog it appears that this CentOS 4.x / Cyrus / Sendmail log
is very different from the Red Hat sendmail-8.11.6-27.72.

30/10/2006, 13h42	#4
J.R0wan Messages: n/a Hébergeur:	Re: Stop sending bounce back message with user unknown Kari Hurtta wrote: > "Simon" <Simon.SM.Li@gmail.com> writes: > >> Hi, >> >> I would like to know is it possible to configure in Sendmail to disable >> the bounce back message to sender if the recipient is unknown "550 >> 5.1.1 <recipient_address>... User unknown". Thanks. > > None. > > Generally bad idea. Will cause that mails to mistyped addresses go to > black hole. > > Perhaps you should look problem from different light ? > > / Kari Hurtta I have the same problem. I receive over 1000 messages a day to randomnames@mydomain.com. This number is growing weekly (I track them before the logs get rotated). I've gone from a few hundred a week to over 20,000 a week. On an impulse I wrote a script to look at the last 1000 lines in /var/log/maillog every 5 minutes and find any occurrenct of "... User unknown". > Oct 30 08:28:13 lazarus sendmail[6422]: k9UDSDd06422: <caninecommendatory@mydomain.com>... User unknown > Oct 30 08:28:13 lazarus sendmail[6422]: k9UDSDd06422: from=<>, size=0, class=0, nrcpts=0, proto=SMTP, daemon=MTA, relay=sv203.lolipop.jp [202.181.96.40] Since (on my server) the next line usually contains the sending party's information, I pull the FQDN, IP Address, bogus email address (from prior line) and the timestamp from the bounce. As there can be numerous "User unknown" messages from that address I write the all to a MySQL database then add new ones to a table which has a unique index defined on the IP address. I take the IP Address from the unique table and add it to IPTables blocking everything from that source. I wanted to do this on another server I support but after looking at /var/log/maillog it appears that this CentOS 4.x / Cyrus / Sendmail log is very different from the Red Hat sendmail-8.11.6-27.72.