OT: Sendmail gateway using mailertable and access db

Jens Ahlin mailing_lists+mailscanner at caleotech.com
Thu Nov 23 07:51:51 GMT 2006

>> OT: Sendmail gateway using mailertable and access db
>> Hi All,
>> I have a MailScanner box (CentOS 4) with sendmail-8.13.1-3 acting
>> gateway in front of an Exchange server (Not my decision). Now all mails
>> for all domains handled are scanned and forwarded to the exchange
>> server. Lately the amount of mail for unknown recipients has exploded
>> over the roof and I need to implement  a quick solution. The server is
>> dying and I don't want to be "that guy" that send undeliverable reports
>> for spam/virus.
>> I'm using access db for another installation and it works fine there but
>> the MailScanner box is not a gateway. All mails are delivered locally.
>> Now with a sendmail installation in gateway mode this doesn't work. I
>> have a script that pulls all valid email addresses from the exchange
>> server and want to use access db to block all but my valid users. I have
>> looked at milter-ahead  but I could not figure out if this is the right
>> thing for me.
>> My config using test.com as domain and xxx.xxx.xxx.xxx as the Exchange
>> server IP address.
>> mailertable:
>> test.com smtp[xxx.xxx.xxx.xxx]
>> access db:
>> test.com     RELAY
>> xxx.xxx.xxx.xxx     RELAY
>> TO:user at test.com    RELAY
>> TO:test.com         ERROR:5.1.1:550 User unknown
>> I have no "relay" FEATURE in my sendmail.mc.
>> Using this config results in all mails sent to user at test.com are
>> rejected with error 550 User unknown.
>> I have read the sendmail documentation regarding access db and tried a
>> lot of different settings (Only TO:, Only Connect:, TO: and Connect:)
>> Any idea of how to do this?
>>         Jens
> Having just gone done this route I can verify it works when you also put
> the
> domain in /etc/mail/relay-domains without that it will reject.
> As far as the LDAP, milter-ahead etc... arguments it seems to me that if
> you AD
>   does not change very often then the Net::LDAP dump to /etc/mail/access
> with a
> makemap afterwards is the great low resource solution.
> I did this on a domain that was getting 170,000+ emails per day [thanks to
> this
> recent spam spike] it is now dropping 115,000 at the gateway. No extra
> ldap
> lookups, no fuss.
> Good Luck.
> -Mike
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Thanks for your suggestions. You are right Mike. As soon I put my relay
domains in relay-domains it works great with the access db. I figured this
out eventually and just before you sent the email. I will look at other
solutions when I have more time (If it ever will happen). For now this is
good enough solution since the system is quite static.

Thanks all for suggestions.


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