MailCat
MailCat is a free, open-source, self-hostable temporary email service built specifically for AI agents.
About
MailCat is a free, open-source, self-hostable temporary email service built specifically for AI agents. Agents can create mailboxes via a single API call with no signup required, then receive emails and auto-extract verification codes and action links. Emails auto-delete after 1 hour for privacy. Deployable on Cloudflare in minutes, and MIT licensed — zero vendor lock-in by design.
Agents that need a throwaway email address for a single workflow — signing up for services, receiving OTP codes, or testing email integrations — where a temporary address is acceptable and free self-hosting matters more than persistent identity.
Pros & Cons
Pros
- check Completely free and open source (MIT license) — no usage costs for the self-hosted path
- check Truly no-signup: an agent can create a mailbox, use it, and move on without any human provisioning
- check Auto-extraction of verification codes and action links is purpose-built for agent workflows (e.g., sign up for a service, get OTP, continue)
- check 1-hour auto-delete means no long-term email storage liability
- check Cloudflare deployment means globally distributed, fast, and costs near-zero at typical agent scale
Cons
- close Temporary email addresses only — not suitable for building a persistent email identity or ongoing correspondence
- close 1-hour deletion window can be too short for multi-step agent workflows that span sessions
- close Cloudflare-based deployment requires a Cloudflare account and some infrastructure setup for self-hosting
- close No persistent storage or threading — designed for ephemeral use, not long-term inbox management
More Email
Other tools in the same category.
