Mailbutler vs Folder Suggest: Which Outlook Add-In Is Better for Email Filing?
Mailbutler is a paid email productivity suite with AI composing, tracking, and scheduling. Folder Suggest is a free add-in focused entirely on AI-powered email filing. Here's how they compare — especially if filing emails into folders is what you need most.
If you've searched for Outlook add-ins that use AI, you've likely come across both Mailbutler and Folder Suggest. They're both listed on Microsoft Marketplace, both use AI, and both aim to make email more manageable. But they're built for different purposes.
Mailbutler is a broad productivity suite — think of it as a Swiss Army knife for email. Folder Suggest is a specialist tool — it does one thing (folder filing) and does it well. This comparison helps you decide which matters more for your workflow.
What Is Mailbutler?
Mailbutler is an email productivity add-in available for Outlook (New Outlook only) and Apple Mail. It bundles several AI-powered features into a single subscription:
- Smart Compose. AI-generated email drafts and replies.
- Email Summarisation. Condense long email threads into key points.
- Email Tracking. See when recipients open your emails.
- Send Later. Schedule emails to send at a specific time.
- Signatures. Professional email signature templates.
- Tasks & Notes. Attach tasks and notes to emails.
- Contacts. Enriched contact information sidebar.
Mailbutler's AI features are cloud-based — email content is processed on Mailbutler's servers to generate summaries and drafts. The free tier includes limited AI credits; paid plans range from $5 to $14/user/month.
One significant limitation: Mailbutler dropped support for Classic Outlook for Windows. It currently works only in New Outlook for Windows and Apple Mail. If your organisation still uses Classic Outlook — which many enterprises do — Mailbutler isn't an option.
What Is Folder Suggest?
Folder Suggest is a free Outlook add-in with a single purpose: help you file the email you're reading into the right folder. It uses an on-device semantic AI model to compare the current email against the content already in your folders, then shows a ranked list of suggestions. One click moves the email.
Key differences from Mailbutler's approach:
- Filing-focused. No composing, tracking, or scheduling — just folder suggestions.
- On-device AI. The model runs locally. No email content is sent to any server.
- All Outlook versions. Works in Classic Outlook, New Outlook, Outlook on the web, and Mac.
- Free. No tiers, no credits, no per-user fees.
- No setup. Works immediately after installation from Marketplace.
Mailbutler vs Folder Suggest: Head-to-Head
| Feature | Mailbutler | Folder Suggest |
|---|---|---|
| Primary purpose | Email productivity suite (compose, track, schedule) | AI-powered email filing into folders |
| AI filing / folder suggestions | ✗ Not a core feature | ✓ Core feature |
| AI composing / summarising | ✓ Yes | ✗ Not available |
| Pricing | Free (limited) / $5–$14/user/month | Free |
| AI processing | Cloud-based (Mailbutler servers) | On-device (nothing leaves your machine) |
| Classic Outlook support | ✗ Dropped — New Outlook only | ✓ Yes |
| New Outlook support | ✓ Yes | ✓ Yes |
| Outlook on the web | ✗ Not supported | ✓ Yes |
| Mac support | ✓ Via Apple Mail | ✓ Via Outlook on the web |
| Email tracking | ✓ Yes | ✗ Not available |
| Send Later | ✓ Yes | ✗ Not available |
| Setup required | Account creation + Mailbutler login | None — install from Marketplace |
Key Differences Explained
Productivity suite vs. specialist filing tool
Mailbutler tries to do many things: compose emails with AI, track opens, schedule sends, manage contacts, and attach tasks. Email filing into folders isn't one of its core features. Its AI is focused on writing and summarising, not on understanding your folder structure.
Folder Suggest does one thing: suggest the right folder for the email you're reading. Its entire AI model is trained for semantic similarity matching — comparing what an email is about against the content in each of your folders. If filing emails into folders is your bottleneck, Folder Suggest addresses it directly. If you need help writing emails, Mailbutler addresses that instead.
Classic Outlook compatibility
This is a dealbreaker for many users. Mailbutler dropped support for Classic Outlook for Windows and now only works in New Outlook. Many enterprises haven't migrated yet — some won't for years. If your organisation uses Classic Outlook, Mailbutler won't work.
Folder Suggest supports Classic Outlook, New Outlook, and Outlook on the web. It also works on Mac via Outlook on the web. This cross-platform coverage means it works regardless of where your organisation is in the New Outlook migration.
Cloud AI vs. on-device AI
Mailbutler's AI features require sending email content to Mailbutler's servers for processing. This is necessary for compose and summarise features — the AI models are too large to run locally. But it means your email content transits through a third party's infrastructure.
Folder Suggest's AI model (~20 MB) runs entirely on your device within the Outlook add-in. No email content, metadata, or folder names are ever sent externally. For users or organisations with data privacy requirements, this is a meaningful distinction.
Cost
Mailbutler's free tier is limited to a handful of AI credits per month. Meaningful use requires a paid plan ($5–$14/user/month). For a team of ten on the Professional plan, that's roughly $1,680/year.
Folder Suggest is free with no limits. Organisations can deploy it via the Microsoft 365 Admin Center at zero cost per user.
Who Should Choose Mailbutler?
Mailbutler is the better fit if:
- You need AI help writing emails, not filing them
- Email tracking and read receipts are important to your workflow
- You use New Outlook for Windows or Apple Mail (not Classic Outlook)
- You want a broad productivity suite rather than a single-purpose tool
- Scheduled sends and task management are features you'll use regularly
Who Should Choose Folder Suggest?
Folder Suggest is the better fit if:
- Your main need is filing emails into the right Outlook folders
- You use Classic Outlook, New Outlook, or Outlook on the web
- You want a free tool — no subscription, no per-user cost
- Privacy matters — you need on-device AI with no cloud processing
- You want something that works immediately with your existing folder structure
- You prefer a focused tool that does one thing well over a broad suite
Can You Use Both?
Yes. Mailbutler and Folder Suggest don't overlap in functionality. You could use Mailbutler for composing, tracking, and scheduling, and Folder Suggest for filing emails into folders. Since Folder Suggest is free, adding it alongside Mailbutler costs nothing extra.
That said, if email filing is your primary concern and you're currently paying for Mailbutler mainly for its AI features, Folder Suggest may cover what you actually need — at no cost.
Verdict
Mailbutler is a capable email productivity suite for users who need AI composing, email tracking, and scheduling on New Outlook or Apple Mail. Its filing capabilities are limited, and it doesn't support Classic Outlook.
Folder Suggest is the better choice if your primary need is filing emails into existing Outlook folders. It's free, works across all Outlook versions, processes everything on-device, and requires no account creation. For anyone looking for a free Mailbutler alternative focused on email filing — especially Classic Outlook users — Folder Suggest is worth trying.
Need AI-powered email filing that works in Classic Outlook, New Outlook, and the web? Folder Suggest is free and requires no setup.
Add to Outlook — Free