JMAP for Mail
JMAP for Mail (RFC8621) is an extension to the JMAP Core protocol that allows users to manage their email accounts using the JMAP API. The extension covers uploading, deleting, and listing emails, as well as managing mailboxes and related settings. Message-level limits and mailbox-shape constraints are carried on the Email singleton (found in the WebUI under Settings › Email › Defaults, Settings › Email › Encryption, Settings › Email › Limits, Settings › Email › Storage); JMAP request-parsing limits are carried on the Jmap singleton (found in the WebUI under Settings › Network › JMAP › Limits, Settings › Network › JMAP › Push, Settings › Network › JMAP › WebSocket).
IMAP and POP3
IMAP protocol settings cover request handling, authentication, timeouts, and rate limits. Several of these settings also apply to the POP3 server, as both protocols share the same configuration surface. IMAP and POP3 settings are carried on the Imap singleton (found in the WebUI under Settings › Network › IMAP). Default special-use folders, which are used by IMAP clients as well as JMAP, are configured on the Email singleton (found in the WebUI under Settings › Email › Defaults, Settings › Email › Encryption, Settings › Email › Limits, Settings › Email › Storage).
Rate limiting
Rate limiting is a strategy to limit network traffic by capping how often a given action (for example, a login attempt) can be repeated within a time window. Rate limiting helps mitigate abuse such as brute-force attacks and reduces load on the mail server.
Maintenance
Stalwart includes an automated maintenance process that manages and optimises the use of server space. The process runs on a schedule to maintain the performance and reliability of the mail server, and performs several functions across user accounts.