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one of my customer have sent an email and later receive delivery failure with this error:
Undelivered Mail Returned to Sender
5.7.20 Massmail must be sign via DKIM
The status is not defined in RFC 3463.
The delivery failure is originating by remote server, not from my SmarterMail server.
It's because remote server need DKIM ?
I need to implement DKIM for my customer ?
GRAFFITI — It's Communication
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