--- The message cannot be delivered to the following address. ---
firstname.lastname@example.org Mailbox unknown or not accepting mail.
550 5.1.1 <email@example.com>... User unknown
Diagnostic-Code: X-Notes; Cannot route mail to user (firstname.lastname@example.org).
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Follow the instructions to read the message.
File attachment: data.zip
The file attached to this email was removed
because the file name is not allowed.
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