Email AI comes in four shapes: an assistant inside your mail app, an AI-first mail client that replaces it, an agent that triages and acts on its own, and writing tools that improve what you type. Start with the mail app you already use.
On Gmail, Google AI Pro ($19.99/mo) brings Gemini into Gmail and Docs. On Outlook, Microsoft 365 Premium ($19.99/mo) adds Copilot to the full Office apps. For a faster client on top of Gmail or Outlook, Superhuman ($30/mo per user) is built around AI drafting and triage. To hand off inbox triage and scheduling entirely, Lindy builds an email agent without code.
| App | Free tier | Paid from | Top plan | Best for |
|---|---|---|---|---|
| Gemini | Yes | $4.99/mo | $99.99–199.99/mo | Google ecosystem users, video generation, very long documents (1M tokens) |
| Copilot | Yes | $19.99/mo | $99.99/mo | Excel data, Word drafting, PowerPoint decks, Outlook triage |
| Superhuman | No | $30/mo | $40/mo | Founders, executives and sales pros who live in email and want AI drafting, triage and scheduling to get through their inbox faster |
| Lindy AI | Yes | $29.99/mo | $29.99/mo | Inbox triage, meeting scheduling, and repetitive multi-step workflow automation |
| Grammarly | Yes | $30/mo | $30/mo | Non-native and casual writers who want real-time grammar, tone, and clarity fixes everywhere they type |
| Wispr Flow | Yes | $15/mo | $23/mo | Professionals who want to draft emails, messages, and documents by voice instead of typing, across desktop and mobile |
Monthly prices in US dollars before tax, from each vendor's official pricing (US list price; weekly-billed plans converted to a monthly figure). Updated November 2, 2026
AI Pro puts Gemini inside Gmail and Docs, with a 1M-token context window, Deep Research and 5 TB of storage in the same plan.
Pick it if: your inbox is Gmail.
Where it falls short: Gmail integration is listed on AI Pro, not the cheaper AI Plus, and the UI changes constantly.
Full Gemini pricing →Copilot is built for Outlook triage and Word drafting, and M365 Premium includes the full Office apps, advanced Copilot chat and up to 6 TB of shared OneDrive storage.
Pick it if: you live in Outlook and Office.
Where it falls short: Only the plan owner gets the Copilot AI, not the family members who share Office.
Full Copilot pricing →A keyboard-first email client for Gmail and Outlook with Superhuman AI, calendar and scheduling from Starter ($30/mo per user). Business ($40/mo per user) adds its most advanced AI: Auto Drafts, Ask AI, custom auto labels and CRM integrations.
Pick it if: you live in your inbox and want a faster client, not just a writing helper.
Where it falls short: No free plan, it's steep for an email client, and Auto Drafts and Ask AI require Business.
Full Superhuman pricing →A no-code "AI employee" builder for inbox triage, meeting scheduling and multi-step workflows across 1,500+ apps. Team starts at $29.99/mo for 3,000 pooled credits a month.
Pick it if: you want email sorted and answered by an agent, not just drafted.
Where it falls short: Free is a one-time credit grant that expires after 7 days, and usage-based Team pricing can scale quickly.
Full Lindy AI pricing →Real-time grammar, spelling and tone detection everywhere you type, free. Pro ($30/mo) adds full-sentence rewrites and tone adjustment.
Pick it if: you write a lot of client email and care how it comes across.
Where it falls short: AI rewrites are generic next to a real LLM, and Pro's monthly list price is steep.
Full Grammarly pricing →Turns speech into polished, formatted text in any app, built for drafting emails and messages by voice on desktop and mobile. Free covers 2,000 words a week on desktop; Pro ($15/mo) is unlimited.
Pick it if: you answer a lot of email and speak faster than you type.
Where it falls short: Accuracy reviews are mixed, and some features capture screen context, which raises privacy questions.
Full Wispr Flow pricing →Inbox agents read and send mail on your behalf. Meta Muse, for example, asks for deep access to email, calendar and browsing, and Lindy connects to 1,500+ apps. Start with drafting help inside your mail app, and add an agent only for a narrow job such as triage or scheduling.
Grammarly Free checks grammar, spelling and tone wherever you type, and Wispr Flow Free allows 2,000 words of dictation a week on desktop. Lindy's free tier is a one-time credit grant that expires after 7 days, so treat it as a trial. Superhuman has no free plan.
Follow your mail app. Gemini's Gmail integration comes with Google AI Pro; Copilot targets Outlook and comes with the full Office apps in Microsoft 365 Premium.
How we choose: prices come from each vendor's official pricing page and are re-checked every week. We take no affiliate fees, so rankings aren't for sale.