You can cut down significantly on SPAM by simply dropping any email with a gtld which didn't exist prior to 2001. Give it a try!
On Dec 4, 2017 22:57, "Stephen Satchell" <l...@satchell.net> wrote: > On 12/04/2017 06:47 PM, Lyndon Nerenberg wrote: > >> Last week we found out that Helpscout sends email from AWS servers. >> >> Thank you, Helpscout, for forcing me to lift the AWS blocks on my >> incoming MTAs, that were cutting down my incoming spam scanning load by a >> factor of two. At least. >> > > If I may make a suggestion: rate-limit incoming connections from AWS, > with a pinhole for Helpscout. Spammers try only one if they are doing > direct SMTP; legit mail servers will retry failed transmissions. > > I used to do this with Postfix at the edge of a Web host network. > > (Yes, yes, I know that compromised PHP scripts will inject mail into a > real mail server, so rate-limiting only spreads out the pain.) >