Definition
Paid email on sift.mx means authenticated messages from unknown senders are held until they pay the cover you set. After payment, the message is privately forwarded to your verified inbox.
The cover is per message
When someone emails your @sift.mx address and is not whitelisted or blocked, sift.mx checks authentication (including SPF, DKIM, and DMARC signals), then holds the message behind a payment challenge for that specific delivery.
If they pay, the full cover transfers to you and the mail is forwarded. If they do not, it stays quarantined until it expires and is removed.
Your real inbox stays private
Senders only ever see your sift handle. Forwarding uses opaque reply addresses so normal correspondence does not leak your destination address.
Not a newsletter paywall
This is not charging subscribers for content. It is charging strangers for access to your attention—while colleagues, customers on your whitelist, and known domains keep flowing free.