SMTP Error Code: 421 2.3.1

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Lookup for "421 2.3.1"

This status code indicates a successful delivery or other operation. Any details are simply notes.

Basic Status Code Details (421)

Service not available, closing transmission channel [This may be a reply to any command if the service knows it must shut down]

Enhanced Status Code Details (2.3.1)

Mail system full

Mail system storage has been exceeded. The general semantics imply that the individual recipient may not be able to delete material to make room for additional messages. This is useful only as a persistent transient error.