Blocking Sendy as spammailer / 2020-08-01

The spam trying to sell me PC hardware keeps going on and I had a closer look. I noticed they all were sent with the following header line:

X-Mailer: Sendy (https://sendy.co)

I had a look through the last months of valid mail and spam mail: 1 valid mail using Sendy, 87 already seen as spam and 104 reports to spamcop. Those are clear numbers, so I created some spamassassin rules:

header LOCAL_MAILER_SENDY X-Mailer =~ /^Sendy \(https:\/\/sendy\.co\)$/
score LOCAL_MAILER_SENDY 1
describe LOCAL_MAILER_SENDY Sendy mailer

Starting with adding 1 for using sendy, but I can add more. Reporting the 'PC hardware' spammers again and again and again via spamcop to charter.net hasn't helped yet.