450 Requested mail action not taken: mailbox unavailable Insufficient security or privacy level

Reason

The connection was rejected because the requirements for EMiG (E-Mail Made in Germany) were not met.

Solution

As a rule, this error occurs in connection with incorrect encryption or encryption that does not meet the requirements. Furthermore, the MX DNS setup may be incorrect with regard to the specifications for EMiG.

Please therefore check the configuration of your mail system with regard to the two aspects mentioned.