Shortwave alternative: for inboxes beyond Gmail

Shortwave deserves genuine credit for building the closest thing to prompt-based sorting we found among mainstream competitors: its AI filters let you organize mail “using natural language descriptions, traditional search queries, or a combination of both,” and each affected thread has an “AI Filters” tab showing which filter fired and why. That’s real, sourced transparency, and it’s the same underlying idea AI Email Filter is built around. Where Shortwave narrows is scope: it’s a full replacement email client, not a layer on top of your existing one, and by its own documentation it “only works with Gmail and Google Workspace” — Microsoft 365 and Exchange “are not supported at this time,” and other providers require forwarding mail into Gmail first.

Where Shortwave shines

• Natural-language AI filters with visibility. You can describe a category in plain English, and Shortwave shows you, per thread, which filter applied — a genuinely transparent mechanism, not a black box.
• A full, polished email client. Shortwave replaces your mail client outright, with AI-powered search, autocomplete, summaries, and attachment analysis built directly into a desktop and mobile app.
• Compliance posture. Shortwave states it meets CASA Tier 2 requirements and includes image-proxy and tracking-pixel blocking as privacy features.
• Deep third-party integration. Slack, Notion, Asana, HubSpot, and calendar integrations, plus a Tasklet partnership connecting to “3,000+ apps,” go beyond what a pure sorting tool offers.

Where it falls short

• Gmail and Google Workspace only, natively. Shortwave’s own documentation confirms Microsoft 365/Exchange aren’t supported, and other providers (Yahoo, iCloud, Fastmail, Zoho, Outlook.com, ProtonMail) only work by forwarding mail into a Gmail account first — not as a direct connection.
• No self-hosted mail server support. With no IMAP option at all, a Mailcow or other self-hosted server is simply out of reach, forwarding included.
• AI filter count is a paid, tiered limit. The number of AI-powered filters you can run is capped by plan: 3 on Business ($30/seat/mo), 10 on Premier ($45/seat/mo), 50 on Max ($120/seat/mo) — categorizing more kinds of mail costs more per seat.
• No bring-your-own-LLM. Filtering and AI features run on Shortwave’s own stack; there’s no published option to choose the underlying model.
• No documented undo/history for filter actions. Shortwave documents “undo send” (reverting a sent message within 10 seconds) and a per-thread filter-audit view, but not a persistent action history with one-click revert for filter-driven moves.

Shortwave vs AI Email Filter

Facts checked directly against shortwave.com and its documentation as of September 2026.

Who should pick which

Shortwave is the better fit if you’re fully on Gmail or Google Workspace, want to replace your email client entirely rather than layer a sorter on top of it, and value deep integrations with Slack, Notion, and similar tools alongside AI search and drafting.

AI Email Filter is the better fit if your mailbox is Yahoo, ProtonMail, or a self-hosted server (Outlook support is coming soon via Microsoft sign-in), if you’d rather keep your existing email client than switch to a new one, or if per-seat pricing and tiered filter limits don’t fit a smaller budget — unlimited categories are included at every paid tier.

FAQ

Can Shortwave connect to Outlook or a self-hosted mail server?

Not natively. Shortwave’s own documentation states Microsoft 365 and Exchange “are not supported at this time,” and non-Gmail providers require forwarding mail into a Gmail account first. There’s no IMAP option, so self-hosted servers like Mailcow aren’t reachable at all.

Does Shortwave really use natural-language filters like AI Email Filter?

Yes, and it’s the closest match among the tools compared here — Shortwave lets you describe filters in plain English and shows a per-thread record of which filter applied. The main differences are provider scope (Gmail-only vs. any IMAP) and pricing model (per-seat with tiered filter caps vs. unlimited categories per account).

How many AI filters can I run on Shortwave before it costs more?

Three on the $30/seat/month Business plan, ten on Premier ($45/seat/mo), and fifty on Max ($120/seat/mo), per Shortwave’s own pricing page. AI Email Filter doesn’t cap the number of categories you can define at any plan tier.

Try prompt-based sorting on any provider

AI Email Filter includes 200 free classifications with no credit card required, so you can test natural-language sorting on Gmail or a self-hosted mailbox — not just Gmail. (Outlook support is coming soon via Microsoft sign-in.) See pricing for unlimited plans starting at $6/month. For more, see Multi-Action Rules, Sender Smart Categories, and private, prompt-based email sorting.