What it does
Himalaya is an open-source command-line email client supporting several account protocols. Its documentation covers sending prepared MIME messages and using an external composer for signing and encryption.
Himalaya separates mailbox operations from richer message composition. Simple mail can be composed with its commands, while signed or encrypted MIME can be prepared by a composer such as MML and then passed to message sending or draft storage.
That is a toolchain for people comfortable with command-line mail, not a claim that every message sent by Himalaya is encrypted automatically. The repository documents several account protocols and provider-specific configuration. Start with the account backend and the chosen cryptographic composer before putting the command into an automated correspondence workflow.
For Proton Bridge, the README uses the password generated by Bridge and a local IMAP/SMTP endpoint. It explicitly distinguishes that credential from the Proton account password, a useful detail when adapting a saved configuration.
Strengths
- Prepared signed or encrypted MIME can be sent through the mail client.
- Several mail-account protocols and provider configurations are documented.
Watch out for
- Rich cryptographic composition uses an external composer in the documented workflow.
Best for
- Command-line users building a deliberate encrypted-mail workflow
Sources
- GitHub - pimalaya/himalaya: CLI to manage emails · GitHub (Oct 26, 2026)