# Lettera (lettera.dev)

Gives AI agents a persistent real email mailbox with threaded replies, plus signed agent-to-agent message relay.

- Atlas card: https://inite.ai/en/atlas/lettera.dev
- Site: https://lettera.dev
- For: Developers building AI agents that must email people or message other agents.
- Categories: agents
- Use 0/100 · alive 100/100

## Used for

- give an agent a real email address and mailbox
- hold agent-drafted replies for human approval before sending
- send signed messages between agents that are not online together

## Price

- free (read 2026-10-26 on https://lettera.dev/pricing)

## For developers

- MCP server: dev.lettera/relay (namespace; open on 2026-10-26, 7 tools)
- Read 2026-10-26

## MCP server, measured daily

Server: https://api.lettera.dev/mcp, checked every day since 2026-10-26 (1 checks).

- Answered: measuring, 1 daily checks so far
- Median first answer: 246 ms
- Sign-in: none
- Context its tool definitions take: about 2297 tokens (7 tools)
- Tool definitions: B, 83/100
- Failing "annotations": 7 of 7 tools
- Warning "destructive_unmarked": send_message
- Warning "open_writes": send_message, update_profile
- Method: https://inite.ai/en/atlas/mcp/report

## Your data

- Certifications stated: none
- Read 2026-10-26

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Source: INITE Atlas, https://inite.ai/en/atlas/lettera.dev. JSON: https://inite.ai/api/atlas/lettera.dev. MCP: https://inite.ai/api/mcp (atlas_lookup).