At this level
at.sovrn.mail · 3- at.sovrn.mail.defs defs Shared types of the mail records sovrn copies to a person's Atmosphere account (at.sovrn.mail.email, at.sovrn.mail.mailbox).
- at.sovrn.mail.email record One message in a mirrored mail folder, after the JMAP Email (RFC 8621 §4), with the raw RFC 5322 message as a blob. Content is immutable. Header fields longer or more numerous than the limits here are shortened; raw always has the whole message. The record key is the base32 (lowercase, unpadded) of the first 20 bytes of the raw message's SHA-256, so it is the same in every folder and can be recomputed from an export. The folder is the space, so there is no mailboxIds; keywords are not mirrored.
- at.sovrn.mail.mailbox record The mail folder a mirrored-mail space holds, after the JMAP Mailbox (RFC 8621 §2). One per space, written by sovrn as the user. The space key is only a readable slug; this record has the exact names.