📄️ SQL Database
Stalwart Mail Server supports using popular SQL database systems such as mySQL, PostgreSQL, and SQLite as a directory server. This allows you to leverage an existing SQL database to handle tasks such as authentication, validating local accounts, and retrieving account-related information.
📄️ LDAP Server
Stalwart Mail Server supports retrieving account information from an LDAP directory such as OpenLDAP or Active Directory. This allows you to leverage an existing LDAP directory to handle tasks such as authentication, validating local accounts, and retrieving account-related information.
📄️ In-memory
In small setups or for testing purposes, you can use the in-memory directory type to define users and groups directly in the configuration file.
📄️ SMTP and IMAP
When running the standalone version of Stalwart SMTP, it is possible to use an external SMTP, LMTP or IMAP server as a "virtual" directory. This allows you to delegate authentication and address validation to a third-party mail server.