SMTP Error Code: 221 4.7.2

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Lookup for "221 4.7.2"

Temporary Error - This status code indicates a transient issue and may resolve itself.

Basic Status Code Details (221)

Service closing transmission channel

Enhanced Status Code Details (4.7.2)

Mailing list expansion prohibited

The sender is not authorized to send a message to the intended mailing list. This is useful only as a permanent error.