MU
Several Gmail accounts: search, read, draft, send, labels and Google Calendar. Own OAuth client.
Free
2 servers across email and communication & collaboration. The largest is Multi Mail.
Email · Communication & Collaboration
Several Gmail accounts: search, read, draft, send, labels and Google Calendar. Own OAuth client.
Send-only Telegram notifications to one fixed chat. No polling, no recipient override, 2 tools.
The rest either hold an API key issued by the publisher or ask for nothing.
Listed without a verification tick. Read the listing before installing.