SMTP Error Code: 221 5.1.7

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Lookup for "221 5.1.7"

Permanent Error - This status code indicates a permanent issue and is unlikely to resolve itself. You should contact the Email Service Provider.

Basic Status Code Details (221)

Service closing transmission channel

Enhanced Status Code Details (5.1.7)

Bad sender's mailbox address syntax

The sender's address was syntactically invalid. This can apply to any field in the address.