1. In Claude open Settings → Connectors (web: claude.ai/settings/connectors; desktop app: same menu) and click Add custom connector.
2. Fill in Name and URL:
   Namepda-mailCopy
   URLCopy
3. Add the connector, then choose Connect to start OAuth sign-in. Leave optional OAuth client ID and secret empty; the client registers automatically.
4. On the mail.pda.cz authorization page, paste the agent key shown above and choose Authorize with this agent key. This connects the agent you just created with its assigned permissions.
5. The passkey option on that page instead connects your administrator account with full administrator permissions. Use the agent key for a limited connector.
6. In a chat, enable pda-mail and ask "show the mail server capabilities". Step 3 below confirms when this agent has connected.

Run in a terminal (adds the server for the current project; add -s user to make it global):

Then /mcp inside Claude Code should list pda-mail as connected.

For clients that read an MCP config file (Claude Desktop claude_desktop_config.json, project .mcp.json, Cursor, …):

Verify the key without any client — should return the server's capabilities: