Filter emails on ASN
For a few years now I've been plagued by property investment spam, always coming from different sender addresses and domains and different subject lines, making it very hard to filter. I currently have a filter containing over 30 lines and counting! The only consistent commonality is that the IP address in the last Received: line in the headers, and the ip address of the sender's email always belong to AS 16276.
Is there an add-on filter that will enable me to mark all mail from AS 16276 as spam?
Wšykne wótegrona (3)
You can add custom headers to a filter or Classic Search, Ctrl+Shift+F. Add the Received header and test it with search.
http://kb.mozillazine.org/Filters_(Thunderbird)#Custom_headers
Thank you @sfhowes, yes, I could add a custom header "Received:", but that only contains the IP address of the originating MTA. But AS16276 has 144 disjoint blocks of IP addresses and the source of spam can be any IP address in any of those blocks. So that doesn't help.
I think I need an extension that would automatically do an AS lookup on the originating MTA's IP address. Is there such a thing? Would it be feasibe to create?
I'm not aware of such an extension or the difficulty in creating one. Most attempts to create spam filters are inadequate. Myself, I don't use TB's Junk controls, and find the spam management performed by my account providers to be very effective.