Re: faked from addresses getting through to my lists
Charlie, Yes, they are discussion lists. What I'm wonndering is if anyone has done anything to beef up the dist file or accept file format so it checks for more than just the email address of the subscriber. a dist file entry something like this "Senders Name" <email@mydomain.com> 192.168.1.1 (comment) so it checks for not only email address but senders name and IP address as well. With those 3 checks in place it would be pretty darn hard for a spammer to fake it I would think. BTW - the spams I got had also forged the Message-ID: header field. I had been thinking of using SmartList as a spam filter with me being the only recipient in the dist file and all of those on my whitelist being in the accept file. Terry Todd On Tue, Jun 15, 2004 at 09:40:29AM -0400, Charlie Summers wrote:
At 6:35 AM -0400 6/15/04, Terry Todd is rumored to have typed:
Is there a way to only allow mail from me to get through only if it originates from my localhost?
Sure. Write a trivial procmail recipe in rc.local.s00 that does the work checking for specific data in the Received: ehader fields (setting the variable in rc.custom, of course, so the rc.local.s00 file is invoked). Although someone determined can presumably forge that, too, it'll drop the auto-generated spam and such. (The nice thing about SmartList is that you have the source code, and can add to or modify it in any way you wish.)
You didn't make it clear whether this is a discussion list or a one-way "broadcast" list. If it's a broadcast list, you should have already set the list to "moderate" which would have avoided the problem in the first place. If it's a discussion list, you will eventually receive viruses or spam forged from _other_ legitimate (subscribed) addresses, which removes this from being a SmartList problem and makes it a spam problem. We _all_ have that problem...
Charlie
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On Tue, Jun 15, 2004 at 09:43:27AM -0500, Terry Todd wrote:
"Senders Name" <email@mydomain.com> 192.168.1.1 (comment) so it checks for not only email address but senders name and IP address as well. With those 3 checks in place it would be pretty darn hard for a spammer to fake it I would think.
But this would prevent legitimate mail from being sent - certainly I send mail from more than one IP address and smarthost. And sender names often do get faked. Putting in a call to spamassassin or similar in the rc.local files should probably deal with most of the problems. Roger
Zitat von Terry Todd <tlt@badger.tltodd.com>:
Yes, they are discussion lists.
What I'm wonndering is if anyone has done anything to beef up the dist file or accept file format so it checks for more than just the email address of the subscriber.
a dist file entry something like this
"Senders Name" <email@mydomain.com> 192.168.1.1 (comment)
so it checks for not only email address but senders name and IP address as well.
A mailing list system isn't the right place to do such verification. It's the task of the mail server. This feature is also only wishful for a minority because a valid email can come from different mail servers. People are travelling and are using different servers. Your solution will not reduce spam but will produce a lot of adminstrative work for the list admin. It would be also difficult to implement. Werner
participants (3)
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Roger Burton West
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Terry Todd
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Werner Reisberger