Do you need fewer messages demanding attention, drafts waiting in the right threads or better wording for a difficult reply? Those are different purchases. We would choose the job first, then compare the seven options below. A writing helper doesn't necessarily sort an inbox, and a background filter may never write a sentence for you.
This shortlist covers Fyxer AI, Superhuman Mail, SaneBox, Microsoft 365 Copilot, Gemini in Gmail, Grammarly Pro and ChatGPT Business for small and mid-sized businesses. Six have full directory reviews. Gemini is here because it comes with Google Workspace; check the suite already being paid for before adding another tool solely for writing help.
Disclosure: none of this page's links are currently affiliate links. Fyxer, Superhuman and SaneBox have affiliate programs; any future affiliate link will be labelled without changing the facts or order. We haven't tested these tools hands-on. This is a comparison of documentation and prices, not a claim about time we saved using them. Methodology.
Comparison table
| Tool | Best for | Paid price (USD) | Free plan | Source |
|---|---|---|---|---|
| Fyxer AI | Staying in Gmail or Outlook, plus a meeting notetaker | Pro $37/person/mo annual ($49 monthly); Team $64 ($99) | Yes, 400 credits/mo (no inbox sorting) | Pricing pagechecked 2026-10-29 |
| Superhuman Mail | Heavy email users who want a faster email app and team comments | Mail Starter $25/member/mo annual ($30 monthly); Business $33 ($40) | No free Mail plan | Pricing pagechecked 2026-10-29 |
| SaneBox | Cheap background filtering and follow-up reminders on any mailbox (incl. Exchange, IMAP) | Snack $5.42/mo annual ($9.49 monthly), 1 account; Lunch $9.08 ($15.99), 2 accounts | No (7-day trial); no AI drafting | Pricing pagechecked 2026-10-29 |
| Microsoft 365 Copilot | Businesses already on Microsoft 365 and Outlook | Copilot Business add-on $21/user/mo paid yearly ($18 promo to 31 Dec 2026) | Copilot Chat included with eligible plans | Pricing pagechecked 2026-10-29 |
| Gemini in Gmail (Google Workspace)Not yet in our directory | Google Workspace teams who want AI help at no extra tool cost | Workspace Business Starter $7/user/mo, billed monthly (US) | 14-day Workspace trial | Pricing pagechecked 2026-10-29 |
| Grammarly Pro | Polishing and rewriting emails in any app | $12/member/mo billed $144/yr | Yes, 100 AI prompts/mo | Pricing pagechecked 2026-10-28 |
| ChatGPT Business | Drafting tricky emails alongside many other tasks | $20/user/mo annual ($25 monthly), 2-seat minimum | Free ChatGPT exists; Business is paid | Pricing pagechecked 2026-10-26 |
Prices are USD before tax, at standard list rates unless a promotion is identified. “Annual” is the monthly equivalent of a yearly bill. ChatGPT Business Standard keeps its 26 Oct 2026 check: the 28 Oct page didn't show that price to our checker. Premium was confirmed on 28 Oct at $100 annually or $125 monthly. We haven't filled in the missing Standard display with a guess.
Three kinds of AI email help
- Inbox assistants that work in the background. Fyxer AI and Superhuman's Email Assistant connect to your Gmail or Outlook, label or file incoming mail, and leave reply drafts waiting for you. You keep your normal email app. Fyxer also records meetings and writes follow-up emails; Superhuman's Email Assistant adds an auto-archive daily digest and follow-up reminders. SaneBox is the low-cost, non-drafting version of this idea: it files unimportant mail into folders on any mailbox (including Exchange and IMAP), sends a Daily Digest and reminds you when nobody replies.
- AI-first email apps. Superhuman Mail replaces the Gmail or Outlook interface with its own keyboard-driven app (web, Mac, Windows, iOS, Android) and builds AI into it: Split Inbox, Write with AI, Instant Reply, Auto Summarize and reminders, plus Auto Drafts and Ask AI on Business. Best for people who process hundreds of emails a day.
- AI built into your office suite or used on demand. Microsoft 365 Copilot in Outlook and Gemini in Gmail draft, rewrite and summarize when you ask. Grammarly Pro rewrites and checks tone in almost any app. ChatGPT Business is a general assistant you can use for difficult emails. None of these sort your inbox for you.
How to choose
- Check your mailbox. Fyxer works with Gmail and Outlook. SaneBox works with almost any provider, including Exchange, iCloud, Yahoo and IMAP. Superhuman Mail supports only Google-hosted and Microsoft 365-hosted accounts (no on-premises Exchange or alias logins). Copilot needs an eligible Microsoft 365 plan; Gemini needs Google Workspace.
- Keep the email app if that is a requirement. Fyxer, Superhuman Email Assistant, Copilot and Gemini let the team remain in Outlook or Gmail; don't buy a replacement client by accident when nobody intends to switch.
- Count the people whose work needs the paid help. Per-person assistants are more plausible for founders, sales staff and client-facing account managers than colleagues sending only a few messages. Test that need rather than assume every mailbox deserves a seat.
- Read the limits. Fyxer uses monthly credits (400 on Free) after a 3-month unlimited launch offer. Superhuman Starter lacks Auto Drafts and Ask AI, which need Business. Grammarly Pro has 2,000 AI prompts per member a month. ChatGPT Business needs at least 2 seats.
- Compare the commitment, not just the rate: Fyxer Pro is $37 annually versus $49 monthly, and Superhuman Starter $25 versus $30. A monthly pilot with one or two people can establish fit before an annual commitment.
- Read the privacy checklist before connecting client or patient information. Getting the mailbox connected isn't the same thing as having approval to share its contents with another service.
Our picks by situation
Stay in Gmail or Outlook and get meeting notes too: Fyxer AI
Consider Fyxer when the job includes inbox sorting, reply drafts in your tone and meeting records. A free plan exists, but check its feature limits before assuming it tests every paid function. Fyxer says it never sends emails for you. Team at $64 annually adds shared Spaces and a shared follow-up list; decide who needs that common context before upgrading.
You live in email and want speed plus team collaboration: Superhuman Mail
Superhuman is the option here for changing the email app itself. Split Inbox, reminders, read statuses and shared threads with comments support that workflow. Starter is $25 per member a month annually. Business at $33 adds Auto Drafts, Ask AI and HubSpot, Salesforce and Pipedrive connections, plus Grammarly, Docs and Go. There is no free plan. Compare the app change with the in-inbox approach in Fyxer AI vs Superhuman Mail.
You just want a quieter inbox for a few dollars: SaneBox
For filtering rather than drafting, Snack costs $5.42 a month annually or $9.49 monthly for one email account. Lunch at $9.08 covers two. SaneBox moves newsletters, notifications and pitches away from the main inbox, blocks senders and resurfaces unanswered email in the app you already use. It doesn't compose the reply. The 7-day trial is a trial, not a free plan; the Fyxer AI alternatives page compares that boundary with the other options.
Your business runs on Microsoft 365 and Outlook: Microsoft 365 Copilot
Already using Outlook, Word, Excel and Teams? Check Copilot's eligible plan before another assistant. The Business add-on is listed at $21 per user a month paid yearly. An $18 promotion applies to eligible existing Business customers from 1 July to 31 December 2026; don't treat it as the permanent list rate. Microsoft says prompts aren't used for model training. The documented email work is drafting and summarizing, not replacing every background sorter.
Your business runs on Google Workspace: Gemini in Gmail
Gemini in Gmail covers writing and summaries inside Workspace Business Starter. The US rate checked on 28 Oct 2026 is $7 per user a month on monthly billing. Google also advertises introductory offers and a 14-day trial. We would check that existing entitlement before paying twice for basic writing help. Automatic sorting is a separate reason to consider Fyxer or Superhuman's Email Assistant later.
You mainly want better-written emails: Grammarly Pro
Grammarly's job is the wording: tone rewrites, grammar corrections and generation in Gmail, Outlook and most other apps. Pro is $12 per member a month annually, and a free plan exists. Check overlap before subscribing separately, because Grammarly is part of Superhuman and is included with Superhuman Business. That bundle only helps the budget if its features are ones you would actually use.
You want one AI for everything, email included: ChatGPT Business
ChatGPT Business is a broader assistant, not an inbox manager. It can help with a complicated reply, proposal or summary from supplied material or connected apps. The seat rate is $20 a month annually or $25 monthly, with a minimum of 2 seats. We would choose it for that general work rather than expect it to keep the mailbox sorted automatically.
Privacy and GDPR checklist
- Fyxer AI: SOC 2 Type II, ISO 27001 and GDPR stated on its site; EU-region data storage only on Enterprise; says it never sends emails for you (checked 28 Oct 2026).
- Superhuman: SOC 2 Type 2 and GDPR stated; public Data Privacy Addendum (effective 8 July 2026) with Standard Contractual Clauses and EU-U.S. Data Privacy Framework certification; data may be processed in the US; help center says neither Mail nor any vendor trains on your data. SSO and BYOK are Enterprise.
- SaneBox: says it analyses only email headers and never stores bodies or attachments, and passes Google's annual security assessment; offers a Data Processing Addendum for businesses, but its privacy policy dates from February 2021, still cites Privacy Shield and doesn't state where data is processed; no SOC 2 or ISO 27001 claim found (checked 29 Oct 2026).
- Microsoft 365 Copilot: Microsoft says prompts and responses aren't used to train foundation models and are covered by Enterprise Data Protection, which includes its GDPR commitments.
- Everyone: sign the vendor's DPA, check the sub-processor list, and ask your Google or Microsoft admin to approve the app before staff connect client mailboxes.
What a 5-person team pays
On annual billing at the list prices above: Fyxer Pro 5 × $37 = $185 a month; Superhuman Mail Starter 5 × $25 = $125; Superhuman Business 5 × $33 = $165; SaneBox Snack 5 × $5.42 = $27.10 (one account each, filtering only); Microsoft 365 Copilot Business add-on 5 × $21 = $105 on top of Microsoft 365 (5 × $18 = $90 on the 2026 promo); Grammarly Pro 5 × $12 = $60; ChatGPT Business 5 × $20 = $100. Gemini comes with your Workspace plan (5 × $7 = $35 on Business Starter, billed monthly).
Don't rank the totals as if they bought the same service. Copilot and Gemini require the Microsoft or Google plan underneath; Superhuman Business includes Grammarly, Docs and Go as well as Mail. Use Fyxer AI alternatives for the email-specific choice, the best AI tools for small business guide for the wider stack, or the monthly price-change log to inspect recorded changes. Compare the work and commitment beside the price, not after choosing the smallest number.
FAQ
What is the best AI email assistant for a small business?
Choose the part of the inbox workflow that needs fixing. For Gmail or Outlook plus meeting notes, start with Fyxer AI (free plan, Pro $37 per person a month on annual billing). If you want a faster email app with team comments and follow-up reminders, Superhuman Mail starts at $25 per member a month on annual billing. If you only want a quieter inbox and follow-up reminders, SaneBox filters almost any mailbox from $5.42 a month on annual billing, but it doesn't draft replies. Prices checked 29 Oct 2026.
What is the best AI email assistant for Outlook?
If you already pay for Microsoft 365, try Microsoft 365 Copilot in Outlook first; the Copilot Business add-on is $21 per user a month paid yearly ($18 promo until 31 Dec 2026). Fyxer AI and Superhuman's Email Assistant both work inside Outlook for Microsoft 365 accounts. Superhuman Mail doesn't support on-premises Exchange. For filtering on any Exchange or IMAP mailbox, SaneBox works through ordinary Outlook folders. More options: our Fyxer AI alternatives page.
What is the best AI email assistant for Gmail?
Google Workspace plans include Gemini in Gmail (Business Starter is $7 per user a month billed monthly in the US). For automatic sorting and reply drafts, Fyxer AI and Superhuman (Mail app or Email Assistant) both work with Gmail.
Do AI email assistants send emails without asking?
Fyxer says it never sends emails for you. Superhuman says Email Assistant drafts are never sent automatically. Copilot, Gemini, Grammarly and ChatGPT write when you ask. Check the settings and keep review between the draft and the external reply before enabling the workflow.
Are AI email assistants GDPR compliant?
Fyxer and Superhuman both state GDPR compliance and SOC 2 Type II. Fyxer offers EU-region storage on Enterprise; Superhuman's DPA says data may be processed in the US. Microsoft covers Copilot under its Enterprise Data Protection terms. Get a DPA signed before connecting client mailboxes.
Is there a free AI email assistant?
Fyxer AI has a free plan with 400 credits a month, Grammarly Free gives 100 AI prompts a month, and Microsoft includes Copilot Chat with eligible Microsoft 365 plans. Superhuman Mail has no free plan, and SaneBox offers a 7-day trial rather than a free plan.