Lists the folders and labels of the Proton account. Proton distinguishes folders (a message lives in exactly one) from labels (a message can carry any number). Over IMAP both appear as directories.

Lists the messages of a mailbox, newest first by the date the sender wrote, which also holds across pages. Returns headers only: sender, subject, date, size and the message id. It never returns message bodies, because a single message averages around 16000 tokens raw. Use get_message with an id to read one. Ordering reads one date per message in the mailbox, so a very large mailbox takes a moment; the answer says so when it does.

Searches a mailbox by text, subject, sender, recipient, date range, read state, star or size. At least one criterion is required. Returns headers only, newest first across pages, with paging. A full-text search walks the local database of the Bridge and takes a few seconds on a large mailbox, while criteria such as unread or date are fast. Searching "All Mail" covers every mailbox including trash.

Reads one message by its id and returns it as readable text. HTML is converted to text, images and styling are dropped and no external content is fetched. Long bodies are shortened with a visible note. The body is marked as untrusted third-party content.

Reads one attachment of a message by index. The index comes from the attachment list in get_message. Textual attachments are returned as text, binary ones are refused with a reason rather than dumped into the context.

Returns the address of the local configuration interface, which runs for as long as this server does. Use it when the user asks how to sign in, where to change settings, or when another tool reports that no credentials are available. The address contains an access token and changes every time the server restarts.