Remote (Streamable HTTP). POST https://mail.example.com/mcp with
Authorization: Bearer <token> (from mcp-mail clients add <id> --for generic). Both
2026-07-28 (stateless, per-request _meta) and initialize-based clients work.
curl -s https://mail.example.com/mcp \
-H "Authorization: Bearer $TOKEN" -H "Content-Type: application/json" \
-H "Accept: application/json, text/event-stream" -H "MCP-Protocol-Version: 2025-06-18" \
-d '{"jsonrpc":"2.0","id":1,"method":"tools/list"}'
Local (stdio). npx -y @annseraf/mcp-mail stdio, with ACCOUNTS_FILE and optional STDIO_PRESET.
Clients that only support OAuth sign-in can use the built-in OAuth server (OAUTH=true); see
claude-ai.md.