AgentButlerAgentButlerFor most people the best AI email assistant is the one already built into the inbox you use. Start there, and only add a separate app if you need more.
| Assistant | Works in | Cost |
|---|---|---|
| Gemini in Gmail | Gmail web and mobile | Some features free; more with Google AI Plus ($4.99/mo) or Pro ($19.99/mo); included in Google Workspace business plans |
| Copilot in Outlook | Outlook | Included in Microsoft 365 Personal ($9.99/mo), Family ($12.99/mo) and Premium; Copilot Business is an add-on for work accounts |
| App | Works with | Cost |
|---|---|---|
| Superhuman | Gmail and Microsoft 365 | From $25 per user/mo billed yearly |
| Shortwave | Gmail and Google Workspace only | Free plan; paid from $18/mo |
| SaneBox | Most providers (IMAP) | Paid, with a free trial; sorting rather than drafting |
ChatGPT and Claude can connect to Gmail (and Outlook in some plans) to search and summarize mail or draft replies. This is useful if you have several accounts and want one assistant for all of them.
Prices are US list prices checked on October 15, 2026 from the vendors' public pages and change often. Always confirm on the official pricing page before you buy. AgentButler has no affiliate deals with any vendor named here.
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