What is "550 SMTP relay service does not allow your IP Address to relay mail to xx" ?

The SMTP service does not allow relay service for those unauthorized users / IP address.

Depend on your smtp service mechanism configuration in RaidenMAILD, you may need :

1. When you smtp server is configured to use SMART SMTP RELAY, you need to receive your mail before sending mail. (POP before SMTP).

2. Your IP should be in the IP Allow List.

3. If your server is configured to enable SMTP AUTH, you can enable "My Server needs authentication" in your mail client.

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