In order to combat spam, we have implemented a mechanism that limits the number of messages you are able to send. You may see a warning message in your personal account if this limit is reached. If you have any questions or concerns about this policy, please do not hesitate to contact our technical support team.
If you encounter any issues while sending messages, you may receive the following error messages:
- When sending via API:
{
  "errors": [
    {
      "code": 429,
      "detail": "Too many messages. Try again in 92 seconds."
    }
  ]
}
When sending via SMTP:
$ telnet smtp.msndr.net 25
  Trying 95.213.163.242...
  Connected to smtp.msndr.net.
  Escape character is '^]'.
  220 smtp.msndr.net ESMTP service ready
  ehlo sender
  250-smtp.msndr.net
  250-STARTTLS
  250-AUTH PLAIN LOGIN
  250-PIPELINING
  250 8BITMIME
  auth plain AHVzZXJAZXhhbXBsZS5vcmcAc29tZS1zdXBlci1wdXBlci1zZWNyZXQta2V5
  550 Too many messages. Try again in 92 seconds.
  Connection closed by foreign host.