Fromboxes

A frombox is an on-chain account for one (recipient wallet, sender “from” address) pair. It holds a prepaid balance of “stamps” and the postage price of a single stamp — sending one email always costs exactly one stamp, so this is the per-email price for that particular sender writing to that particular recipient. Where a mailbox is 1:1 with a recipient, a frombox is 1:1 with a specific sender-recipient relationship — the same mailbox owner can have a different frombox (and a different stamp price) for every sender who writes to them.

New, never-before-seen senders don’t have a frombox at all: the recipient’s mailbox default postage (also a per-stamp price) applies instead, and that default is normally set high specifically to price out spam from unknown senders. Once a recipient knows and trusts a sender, they create a frombox for that sender and set a lower, negotiated stamp price.

Looking up a frombox

sithbit frombox get <from> [to_address]

to_address is optional and defaults to your own address — the recipient’s point of view. For example, to check the frombox a recipient has set up for jane_doe@sithbit.com:

sithbit frombox get jane_doe@sithbit.com

See Appendix: Closing accounts for how to close a frombox and reclaim its rent and remaining stamp value.