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Relaying questions

Printed From: LogSat Software
Category: Spam Filter ISP
Forum Name: Spam Filter ISP Support
Forum Description: General support for Spam Filter ISP
URL: https://www.logsat.com/spamfilter/forums/forum_posts.asp?TID=4266
Printed Date: 06 June 2025 at 2:17pm


Topic: Relaying questions
Posted By: Guests
Subject: Relaying questions
Date Posted: 14 September 2004 at 7:33pm

I'm a new user/tester. Just downloaded this today and got it installed and running. My question is... I want to disable relaying from all hosts by default except for those I explicitly defined as friendly hosts. In another words, I don't want anybody (outside or local) to use my server to send mail to anybody, except those that I defined as being able to (such as local IP ranges, certain external IPs, etc...)

The only thing I could find was "Local Domains", which as I understands, allows me to control who I can send to. I don't understand the logic behind this, as I would like to be able to send to all domains, but only allow certain IP and IP ranges to relay (send outgoing messages) through my server...

Any explanation or help would be appreciated. If I can get this to work or work similarly to what I explain, we will buy this program.


Replies:
Posted By: LogSat
Date Posted: 14 September 2004 at 11:56pm
Tou,

By default SpamFilter ISP will not allow anyone to use it to openly relay emails. That would be a very bad thing for an antispam product :-)

SpamFilter will only allow emails to be delivered (relayed) to the domains listed in the "Local Domains". Those would be the domains you own and control. Any attempt to use SpamFilter to relay an email not addressed to those domains will be denied. Only localhost (127.0.0.1) is allowed to relay email, nobody on the internet or your internal IPs will be able to use it to send email to anyone except to the domains listed in that whitelist.

Some administrators also want to use SpamFilter to scan their outgoing email. Since again by default SpamFilter will not allow email to be sent to other domains, the only way this can be accomplished is by adding the IP addresses that are allowed to relay to an IP whitelist. Only then will those IP be able to send email to the outside world, to domains not listed in the Local Domains list.

I hope this helps.

Roberto F.
LogSat Software

Posted By: Guests
Date Posted: 15 September 2004 at 1:09pm

Robert, thanks for the reply.

That last paragraph there, that's exactly what I'm looking for. Where do I put these IPs that I want to "white list", so they can relay to the outside world? Do I put them in the "Excluded Domains / IPs" tab ? If so, I will try it. Thanks for your help.

 

Posted By: LogSat
Date Posted: 15 September 2004 at 6:05pm
Yes, the "Excluded Domains / IPs" tab is the one you're looking for. Please note that while you can add sender's domain names in there that will bypass incoming filtering rules, they will still not be able to relay to the outside. This is done because if a spammer is able to "guess" what domains you have in that list, they can easily fake a sender's email address from that domain and thus use SpamFilter to relay.

However if you add an IP or a range of IPs in there (the list can have both domains and IPs), then in that case if the sender's IP is going to be able to relay to the outside. It's extremely hard for a spammer in this case to spoof his IP, so that willnot be a concern.

Roberto F.
LogSat Software

Posted By: Lee
Date Posted: 30 September 2004 at 7:42am

Roberto along those same lines...

I added my real internal mail server to the list of whitelist ip's. I then set my mail server to use SF as it's gateway for outbound mail.

The problem is that SF trys to forward that mail back to the mail server resulting in a loop. Shouldn't SP be sending any mail not listed in the local domains outbound not to the destination server listed?

Am I missing some thing?

Thanks,

Lee

Posted By: LogSat
Date Posted: 30 September 2004 at 11:05pm
Lee,

SpamFilter will only forward email to your destination SMTP server, it will not send email out to the internet. That is how SpamFilter was designed. Having your SMTP server use SF as a gateway will indeed cause mail loops.

Some administrators have SpamFilter as the "outgoing smtp server" in their client's email applications, but in that case SpamFilter will still forward the emails to the main SMTP server, which will then relay them to the internet.

Roberto F. LogSat Software


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