mail-server/resources/config/sieve/received.sieve
2023-10-06 16:53:50 +02:00

93 lines
2.7 KiB
Sieve

let "rcvd_raw" "header.received[*].raw";
let "rcvd_count" "count(rcvd_raw)";
# Count received headers
if eval "rcvd_count == 0" {
let "t.RCVD_COUNT_ZERO" "1";
} elsif eval "rcvd_count == 1" {
let "t.RCVD_COUNT_ONE" "1";
} elsif eval "rcvd_count == 2" {
let "t.RCVD_COUNT_TWO" "1";
} elsif eval "rcvd_count == 3" {
let "t.RCVD_COUNT_THREE" "1";
} elsif eval "rcvd_count <= 5" {
let "t.RCVD_COUNT_FIVE" "1";
} elsif eval "rcvd_count <= 7" {
let "t.RCVD_COUNT_SEVEN" "1";
} elsif eval "rcvd_count <= 12" {
let "t.RCVD_COUNT_TWELVE" "1";
}
# Received from an authenticated user
if eval "!is_empty(env.authenticated_as)" {
let "t.RCVD_VIA_SMTP_AUTH" "1";
}
# Received headers have non-ASCII characters
if eval "!is_ascii(rcvd_raw)" {
let "t.RCVD_ILLEGAL_CHARS" "1";
}
let "i" "0";
let "tls_count" "0";
let "rcvd_from_ip" "0";
while "i < rcvd_count" {
let "i" "i + 1";
let "helo_domain" "received_part(i, 'from')";
# Check for a forged received trail
if eval "!t.FORGED_RCVD_TRAIL" {
let "iprev" "received_part(i, 'iprev')";
if eval "!is_empty(iprev) && !is_empty(helo_domain) && !eq_ignore_case(helo_domain, iprev)" {
let "t.FORGED_RCVD_TRAIL" "1";
}
}
if eval "!t.PREVIOUSLY_DELIVERED" {
let "for" "received_part(i, 'for')";
# Recipient appears on Received trail
if eval "!is_empty(for) && contains_ignore_case(recipients, for)" {
let "t.PREVIOUSLY_DELIVERED" "1";
}
}
if eval "!t.RCVD_HELO_USER && eq_ignore_case(helo_domain, 'user')" {
# Received: HELO contains 'user'
let "t.RCVD_HELO_USER" "1";
}
if eval "!is_empty(received_part(i, 'from.ip'))" {
# Received from an IP address rather than a FQDN
let "rcvd_from_ip" "rcvd_from_ip + 1";
}
if eval "!is_empty(received_part(i, 'tls'))" {
# Received with TLS
let "tls_count" "tls_count + 1";
}
}
if eval "rcvd_from_ip >= 2 || (rcvd_from_ip == 1 && is_ip_addr(env.helo_domain))" {
# Has two or more Received headers containing bare IP addresses
let "t.RCVD_DOUBLE_IP_SPAM" "1";
}
if eval "rcvd_count == 0" {
# One received header in a message (currently zero but one header will be added later by the MTA)
let "t.ONCE_RECEIVED" "1";
# Message has been directly delivered from MUA to local MX
if eval "header.User-Agent.exists || header.X-Mailer.exists" {
let "t.DIRECT_TO_MX" "1";
}
}
# Received with TLS checks
if eval "rcvd_count > 0 && tls_count == rcvd_count && !is_empty(env.tls.version)" {
let "t.RCVD_TLS_ALL" "1";
} elsif eval "!is_empty(env.tls.version)" {
let "t.RCVD_TLS_LAST" "1";
} else {
let "t.RCVD_NO_TLS_LAST" "1";
}