http://protonmailrmez3lotccipshtkleegetolb73fuirgj7r4o4vfu7ozyd.onion/support/email-bomb-mitigation
When this filter is applied, the filtered messages will never reach the Inbox, which is why we suggest applying sieve filters for only the duration of the attack: if anyof (
header "x-auto-response-suppress" ["OOF", "AutoReply"],
header "precedence" "bulk",
header "auto-submitted" "auto-generated",
exists "form-sub",
exists "list-unsubscribe",
exists "x-php-script",
exists "x-php-originating-script"
) {
discard;
} 2. A little softer variant...