func makeMailHandler(mandrillAPI *gochimp.MandrillAPI, sendLimiter *rerate.Limiter, spamLimiter *rerate.Limiter) func(smtpd.Peer, smtpd.Envelope) error {
return func(peer smtpd.Peer, env smtpd.Envelope) error {
// Validate data before sending them
if _, err := mail.ReadMessage(bytes.NewReader(env.Data)); err != nil {
return err
}
response, err := mandrillAPI.MessageSendRaw(string(env.Data), env.Recipients, gochimp.Recipient{Email: env.Sender}, false)
if err != nil {
log.WithFields(log.Fields{
"peer": peer,
"error": err,
}).Info("Error sending message")
return smtpd.Error{Code: 451, Message: "Error with Remote API"}
}
if response[0].Status == "rejected" && response[0].RejectedReason == "spam" {
log.WithFields(log.Fields{
"peer": peer,
"RejectedReason": response[0].RejectedReason,
}).Info("Message filtered as SPAM")
if err := spamLimiter.Inc(peer.HeloName); err != nil {
log.WithFields(log.Fields{
"heloName": peer.HeloName,
"error": err,
}).Warn("Can't increment send")
}
return smtpd.Error{Code: 451, Message: "Spam filtered, increment rate limit"}
}
return nil
}
}
func makeHeloChecker(sendLimiter *rerate.Limiter, spamLimiter *rerate.Limiter) func(smtpd.Peer, string) error {
return func(peer smtpd.Peer, heloName string) error {
if err := sendLimiter.Inc(heloName); err != nil {
log.WithFields(log.Fields{
"heloName": heloName,
"error": err,
}).Warn("Can't increment send")
}
if exc, _ := sendLimiter.Exceeded(heloName); exc {
log.WithFields(log.Fields{
"rateLimit": "send",
"peer": peer,
}).Warn("rateLimit exceeded")
return smtpd.Error{Code: 451, Message: "Rate Limit exceeded"}
}
if exc, _ := spamLimiter.Exceeded(heloName); exc {
log.WithFields(log.Fields{
"rateLimit": "spam",
"peer": peer,
}).Warn("rateLimit exceeded")
return smtpd.Error{Code: 451, Message: "Rate Limit exceeded"}
}
return nil
}
}