How Fastmail and Claude Code work together
Claude Code can use MailOS commands to retrieve inbox context from Fastmail, draft useful replies, and ask for confirmation before sending.
Fastmail + Claude Code
Fastmail Claude Code email integration
MailOS connects Fastmail inbox workflows to Claude Code through terminal commands. The result is a safer way for agents to understand email context and prepare outbound messages.
$
npm install -g mailos What this gives you
- Read and search Fastmail from Claude Code workflows
- Prepare drafts with visible review steps
- Use IMAP and SMTP without building one-off scripts
Example commands
mailos search --account [email protected] --subject "follow-up"mailos "Claude Code should summarize unread Fastmail messages"mailos send --drafts --confirm Best use cases
Use this combination for customer support follow-ups, partner outreach, recruiting coordination, founder inbox triage, and project status updates.
Implementation boundary
MailOS keeps provider connection, account selection, draft creation, and final sending as explicit command-level steps rather than hidden browser automation.
FAQ
Questions before wiring email into an agent workflow
Can MailOS send Fastmail Claude Code emails automatically?
MailOS supports send commands, but the recommended agent workflow uses draft, preview, dry-run, and confirm steps before final sending.
Does MailOS replace my email client?
No. It complements your existing inbox by giving terminal tools and AI agents a consistent command interface.
Can I use multiple accounts?
Yes. MailOS is designed around explicit account selection so work, personal, and project inboxes can stay separate.