Update a frombox

sithbit frombox update <from> [required_postage] \
  [--keypair <keypair>] \
  [--skip-preflight]

required_postage is the price (in lamports) of a single stamp — since each email burns exactly one stamp, this is what one send from <from> to you costs. It defaults to 1 SOL if omitted. Use this to lower the stamp price for a sender you’ve come to trust:

sithbit frombox update jane_doe@sithbit.com 100000000

…or to raise it — even above the mailbox’s own default — for a sender who has become a nuisance.