What it accesses.
With the account holder’s authorisation, MailKnow reads mail over IMAP. It never sends, alters, moves or deletes anything: the connection it uses offers no operation that could modify a mailbox.
What it stores, and where.
Message text and metadata are stored on the local computer only. Attachment contents are never downloaded — only the file name, type and size. Access tokens are held in the operating system keyring.
What it transmits.
Nothing. There is no server, no account, no analytics and no third party. Data is not shared, sold or transferred, because it never leaves the machine it was fetched to.