Strict RFC compliance is very simple: (1) When a remote MTA connects it MUST NOT speak until spoken to. (2) A remote MTA MUST NOT violate the command/response protocol. (3) The IP Address of the remote host MUST resolve (in the in-addr.arpa domain) to a name that forward resolves to a set of IP Addresses that includes the originating address. (4) The name given by a remote host in its HELO or EHLO, if not an IP Address, must be resolvable to an IP Address. (5) The domain name given in the envelope-from must be resolvable to an IP Address.
Optional: (6) The IP Address determined by step 4 must accept SMTP connections. (7) The IP Address determined by step 5 must accept SMTP connections. (8) The MTA in step 7 must accept an envelope specifying envelope-to the original envelope sender with an empty envelope-from Enforcing compliance with (1) eliminates >70% of all spam. Enforcing compliance with (2) eliminates an additional 10% of all spam. Enforcing compliance with (3) eliminates an additional 10% of all spam. Enforcing compliance with (4) and (5) eliminates almost another 10% of spam. Enforcing (6), (7), and (8) (that is, requiring full RFC compliance) eliminates 99.99% of spam. If you also can enforce the dropping of direct-to-mx connections (that is, connections to higher numbered MX's should be rejected if a lower number MX MTA is availkable), then you can increase the spam rejection to about 99.999% And this is all without blacklists or other questionable whack-job filtering ... --- The fact that there's a Highway to Hell but only a Stairway to Heaven says a lot about anticipated traffic volume. >-----Original Message----- >From: sqlite-users [mailto:sqlite-users- >boun...@mailinglists.sqlite.org] On Behalf Of Warren Young >Sent: Tuesday, 21 November, 2017 12:43 >To: SQLite mailing list >Subject: Re: [sqlite] Many ML emails going to GMail's SPAM > >On Nov 21, 2017, at 10:24 AM, Peter Da Silva ><peter.dasi...@flightaware.com> wrote: >> >> But the mailers I use (Gmail’s web interface, Apple Mail and (yuck) >Outlook) all do basic threading. > >I’d describe what Apple Mail and Gmail do as “clumping” rather than >“threading.” > >I think we can all agree that drh gets trees, so if he wants to make >a threaded web forum, he certainly needs no advice from us on how to >achieve it. > >The effort to implement Hacker News can’t have been all that great. >It would suffice for our purposes. Do it atop Fossil and you get >user authentication for free, which reduces spam. When (!) spam gets >through, it can be shunned using the normal Fossil mechanism, so that >later clones don’t contain it. > >As far as I can tell, the only really hard part is the email >gatewaying problem, evidenced by the fact that Fossil still doesn’t >have a feature to echo commits, ticket changes, etc. via email. > >The comment up-thread about RFC-complaint email handwaves the >complexity of achieving that in 2017, even when using existing tools, >which is not a given where drh is concerned. > >If you start with Postfix’s RFC list: > > http://www.postfix.org/smtpd.8.html > >then chase all the “obsoleted by” and “updated by” links from those >RFCs and add in completely missing RFCs that are also requirements in >2017, you get this list, which is probably also incomplete, because I >am no expert on MTA implementation: > > RFC 1123 (Host requirements) > RFC 1870 (Message size declaration) > RFC 1985 (ETRN command) > RFC 2034 (SMTP enhanced status codes) > RFC 2920 (SMTP pipelining) > RFC 3207 (STARTTLS command) > RFC 3461 (SMTP DSN extension) > RFC 3463 (Enhanced status codes) > RFC 3848 (ESMTP transmission types) > RFC 3885 (SMTP Service Extension for Message Tracking) > RFC 4954 (AUTH command) > RFC 5321 (SMTP protocol) > RFC 5322 (Internet Message Format) > RFC 6152 (8bit-MIME transport) > RFC 6409 (Message Submission for Mail) > RFC 6531 (Internationalized SMTP) > RFC 6532 (Internationalized Email Headers) > RFC 6533 (Internationalized Delivery Status Notifications) > RFC 7489 (DMARC) > RFC 7504 (SMTP 521 and 556 Reply Codes) > RFC 7505 ("Null MX" No Service Resource Record) > RFC 7817 (STARTTLS updates) > RFC 8098 (Message Disposition Notification) > >Those 23 standards print as 579 pages. Yes, that’s right, someone >“just” has to implement 579 pages of standardese, which gets you only >SMTP, which we’d better hope is enough since IMAPv4 + POPv3 probably >doubles that again. >_______________________________________________ >sqlite-users mailing list >sqlite-users@mailinglists.sqlite.org >http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users _______________________________________________ sqlite-users mailing list sqlite-users@mailinglists.sqlite.org http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users
