The short answer
SaneBox is the cheapest AI email assistant at $9.49 a month for one account, and it sorts your inbox without replacing your email app. Shortwave Pro at $18 a seat a month suits Gmail users who want AI search and drafting. Superhuman from $30 a user a month is the fastest client, but costs the most here.
Key takeaways
- SaneBox Snack costs $9.49 a month billed monthly for one email account and two features.
- Shortwave Pro costs $18 a seat a month, with a free plan that keeps 90 days of search history.
- Superhuman Mail Starter costs $30 a user a month billed monthly, or $25 billed annually.
- Fyxer Pro costs $49 a person a month billed monthly, or $37 billed annually, and its free plan has no drafts.
- Mailbutler's AI assistant starts on the Smart plan at $14 a user a month billed monthly.
Why people look for an AI email assistant
The inbox problem has two halves. The first is volume: newsletters, notifications, and CCs bury the ten emails that actually need a reply. The second is writing: every reply takes a minute to draft, and those minutes add up to hours a week. AI email assistants attack one half or the other. SaneBox and Hiver attack volume by sorting and sharing the inbox. Shortwave, Superhuman, Mailbutler, and Fyxer attack writing by drafting replies, summarizing threads, and letting you search years of email in plain English. Match the tool to the half of the problem that costs you the most time.
What to look for in an AI email assistant
- Sorting or drafting. Decide which job matters more. Sorters such as SaneBox file email into folders; drafters such as Fyxer write replies for you to approve.
- Your email provider. Shortwave and Hiver work with Gmail only. Superhuman works with Gmail and Outlook. Mailbutler runs in Apple Mail, Gmail, and Outlook.
- AI usage caps. Several tools meter AI work in daily requests or monthly credits. A cap that looks generous on paper can run out mid-month for a heavy user.
- Search history. Shortwave's free plan keeps 90 days of search history; paid plans keep three years or more. If you search old email often, this limit matters.
- Team features. Shared inboxes, assignments, and internal notes matter for support teams; they are irrelevant for a solo user.
How we chose
Six tools made this list because each one covers a different corner of the AI email market: the cheapest sorter, the deepest AI search, the Apple Mail and Outlook assistant, the fastest client, the drafts-plus-notes tool, and the shared inbox. Prices, plan names, free-plan limits, and AI caps come from each vendor's pricing page, based on published pricing and documentation, checked on 14 November 2026. No hands-on testing was done. SaneBox and Hiver changed prices during 2026, so the price log records the conflicting figures found.
1. SaneBox: best for hands-off inbox triage
Starting price: From $9.49 a month billed monthly ($65 a year, Snack, 1 email account) · Best for: Hands-off inbox triage · Skip if: You want an AI that drafts replies, because SaneBox only sorts
SaneBox sits on top of whatever email client you already use, whether Gmail, Outlook, Apple Mail, or any IMAP account, and sorts incoming mail into folders such as SaneLater and SaneNews. Snack at $9.49 a month billed monthly covers one account and two features; Lunch at $15.99 covers two accounts and six features; Dinner at $42.99 covers four accounts and every feature, plus phone support.
The limit is scope. SaneBox filters, it never writes a reply, so the writing half of the inbox problem stays yours. The entry plan is also restrictive: one account and only two power tools locks out features such as SaneAttachments and Snooze unless those are your two picks. Most individuals land on Lunch, which costs $15.99 a month billed monthly. There is no free plan, only a 14-day trial with no credit card required.
Skip SaneBox if you want AI drafting. It is the best sorter on this list and the worst drafter, because drafting is not something it does at all.
2. Shortwave: best for AI search across Gmail history
Starting price: From $18 a seat a month (Pro, individual) · Best for: AI search across Gmail history · Skip if: You use Outlook, because Shortwave is Gmail only
Shortwave is a Gmail client built around an AI assistant. You can ask questions about your email history in plain English, get summaries of long threads, and draft replies with AI writing help. Pro at $18 a seat a month adds full search history, three years of AI search history, and 50 threads per AI search. Business at $30 adds team features and more AI usage, Premier at $45 doubles it, and Max at $120 is the top tier. The free plan covers basic AI with a limited quota and 90 days of search history. Shortwave works with Gmail and Google Workspace only, so Outlook and Apple Mail users are locked out. Every plan also caps AI usage with a daily quota, so a heavy user can run out of AI requests before the day ends.
Skip Shortwave if your team uses Outlook. Superhuman below is the closest alternative that supports it.
3. Mailbutler: best for Apple Mail and Outlook users
Starting price: From $5 a user a month billed monthly (Starter); AI assistant from $14 a user a month billed monthly (Smart) · Best for: Apple Mail and Outlook users · Skip if: You want the AI assistant under $14 a user a month
Mailbutler is the only tool on this list that runs natively inside Apple Mail, Gmail, and Outlook as a plugin rather than a separate app. It adds tracking, templates, and signatures, plus an AI Smart Assistant that composes, improves, and summarizes email. Starter costs $5 a user a month billed monthly, Professional $9, Smart $14, and Business $32.
The pricing trap is the tier jump. The AI assistant that justifies the purchase starts on Smart, so the real entry price for AI help is $14 a user a month, not $5. Tracking analytics are also gated to Smart and above.
Skip Mailbutler if you want AI drafting for under $14 a user a month. Shortwave Pro at $18 is dearer, but SaneBox at $9.49 sorts for less, though it never drafts.
4. Superhuman: best for speed-first Gmail and Outlook users
Starting price: From $30 a user a month billed monthly ($25 a user a month billed annually, Starter) · Best for: Speed-first Gmail and Outlook users · Skip if: Your budget is under $25 a user a month
Superhuman is a keyboard-first email client for Gmail and Outlook, sold on one promise: you get through email faster. Starter at $30 a user a month billed monthly, or $25 billed annually, includes Split Inbox, snippets, calendar, scheduling, and core AI writing and summaries. Business at $40 monthly, or $33 annually, adds Auto Drafts, Ask AI, custom AI labels, and HubSpot and Salesforce integrations.
The price is the highest on this list for a single user, and the features that make it an AI assistant rather than a fast client sit on Business. Auto Drafts and Ask AI need the $40 tier, so the tool most people picture when they hear "AI email assistant" costs $33 a user a month billed annually, not $25.
Skip Superhuman if your budget is under $25 a user a month. Shortwave Pro at $18 covers most of the same AI work for Gmail users at a lower price.
5. Fyxer: best for drafts plus meeting notes in one
Starting price: From $49 a person a month billed monthly ($37 a person a month billed annually, Pro) · Best for: Drafts plus meeting notes in one · Skip if: Your budget is under $37 a person a month for drafts
Fyxer drafts replies in your tone, sorts your inbox with labels, records meetings, and writes meeting notes, all in one subscription. Pro at $49 a person a month billed monthly, or $37 billed annually, covers one inbox with 3,000 credits a month after the first three months. Team at $99 monthly, or $64 annually, adds several inboxes and shared team context with 6,000 pooled credits per member. The free plan costs $0 with 400 credits a month for chat and audio meeting notes, but it neither drafts replies nor sorts your inbox.
The meter is the thing to watch. Usage is counted in credits, and 400 free credits buy about 20 chat messages, so the free plan is a test drive rather than a working tool.
Skip Fyxer if your budget is under $37 a person a month. The free plan will not draft a single reply, so the real entry price is Pro.
6. Hiver: best for shared inboxes inside Gmail
Starting price: From $19 a user a month billed annually (Lite) · Best for: Shared inboxes inside Gmail · Skip if: Your team uses Outlook, because Hiver is Gmail only
Hiver turns Gmail into a shared inbox for support and operations teams. Emails can be assigned to teammates, internal notes added, collisions flagged when two people open the same email, and SLAs tracked, all without leaving Gmail. Lite at $19 a user a month billed annually covers the shared inbox basics, Growth at $29 adds analytics and automation, and Pro at $49 adds AI features including the Harvey AI agent. A free plan with a basic shared inbox exists alongside the paid tiers.
Hiver is a collaboration tool with AI features, not an AI-first assistant. It also only works with Gmail and Google Workspace, so an Outlook team cannot use it at all.
Skip Hiver if your team uses Outlook, or if you want an AI that drafts replies. Buy it when three or more people share one support inbox in Gmail.
What five users cost on each assistant
This calculation prices five people for one month, using annual billing where the vendor publishes an annual rate, on the cheapest plan that includes AI help.
| Tool | Per user a month | Five users a month | Five users a year |
|---|---|---|---|
| SaneBox (Snack, annual) | $5.42 | $27.10 | $325 |
| Mailbutler (Smart, annual) | $11 | $55 | $660 |
| Shortwave (Pro) | $18 | $90 | $1,080 |
| Hiver (Lite, annual) | $19 | $95 | $1,140 |
| Superhuman (Starter, annual) | $25 | $125 | $1,500 |
| Fyxer (Pro, annual) | $37 | $185 | $2,220 |
Among tools that draft, Mailbutler Smart at $660 a year for five people is the cheapest, and Fyxer Pro at $2,220 is the dearest, because it bundles meeting recording and notes on top of drafting.
What the free plans really allow
Free tiers in this category range from useful to decorative. Shortwave's free plan is genuinely usable for one person: basic AI, 90 days of search history, and 15 threads per AI search, with a Shortwave signature on sent mail. Fyxer's free plan gives 400 credits a month for chat and audio notes, but no drafts and no sorting, so it shows you the product without doing the job. Mailbutler's free Starter plan covers basic tracking only, and Hiver's free plan covers a basic shared inbox. SaneBox and Superhuman have no free plan at all.
Where AI email buying usually goes wrong
- Paying for drafting you never use. SaneBox costs $9.49 a month and never drafts, while Fyxer Pro costs $49 and drafts everything. Buy the job, not the label.
- Ignoring the provider lock-in. Shortwave and Hiver are Gmail only. A team that moves to Outlook later has to move tools too.
- Missing the AI cap. Shortwave caps daily AI requests, and Fyxer meters credits. Model a busy week before you commit to a tier.
- Pricing the wrong tier. Superhuman's Auto Drafts need Business, Mailbutler's assistant needs Smart, and Fyxer's drafts need Pro. The headline price is rarely the price of the feature you want.
To compare the email marketing side, see the best email marketing platforms for creators and the best mass email service. The email automations guide shows which sequences to automate first, and Adziq's email services cover setup and automation for teams that want it done for them.
AI Email Assistant Tools, Ranked by Budget at a glance
| Pick | Best for | Starting price | Free plan |
|---|---|---|---|
| SaneBox | Hands-off inbox triage | From $9.49 a month billed monthly ($65 a year, Snack, 1 email account) | No, 14-day free trial |
| Shortwave | AI search across Gmail history | From $18 a seat a month (Pro, individual) | Yes, free plan with 90-day search history |
| Mailbutler | Apple Mail and Outlook users | From $5 a user a month billed monthly (Starter); AI assistant from $14 a user a month billed monthly (Smart) | Yes, Starter plan |
| Superhuman | Speed-first Gmail and Outlook users | From $30 a user a month billed monthly ($25 a user a month billed annually, Starter) | No |
| Fyxer | Drafts plus meeting notes in one | From $49 a person a month billed monthly ($37 a person a month billed annually, Pro) | Yes, free plan with 400 credits a month, no drafts |
| Hiver | Shared inboxes inside Gmail | From $19 a user a month billed annually (Lite) | Yes, free plan |
Common questions
What is an AI email assistant?
It is software that uses AI to sort, summarize, search, or draft email for you. Some tools, like SaneBox, only sort your inbox into folders. Others, like Shortwave and Superhuman, are full email clients with AI drafting, summaries, and natural-language search built in.
What is the cheapest AI email assistant?
SaneBox Snack at $9.49 a month billed monthly for one account. It only sorts email, though: it never writes a reply. The cheapest assistant that also drafts is Mailbutler Smart at $14 a user a month billed monthly, and the cheapest full AI client is Shortwave Pro at $18 a seat a month.
Is Superhuman worth $30 a month?
It depends on how much email you process. Superhuman is the fastest client here, with keyboard shortcuts, split inbox, and snippets, and Starter costs $30 a user a month billed monthly. If you clear hundreds of emails a day, the speed may pay for itself. If you answer twenty emails a day, Shortwave Pro at $18 does most of the same AI work for less.
Does Shortwave work with Outlook?
No. Shortwave only works with Gmail and Google Workspace accounts. Outlook users should look at Superhuman, which supports Gmail and Outlook, or Mailbutler, which runs natively in Apple Mail, Gmail, and Outlook.
Can an AI email assistant send email for me?
Fyxer drafts replies but does not send them automatically, and the same is true of the drafting features in Shortwave, Superhuman, and Mailbutler. You review every draft before it goes out. That is a safety feature, not a limitation: an AI that sends on its own could reply to the wrong thread.
Sources
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