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Siftbox · Guides

Spark Mail Alternative: AI Mail Client or Triage Layer?

Spark Mail and Siftbox both use AI against email overload, but they are not the same product. Spark is a mail client to install (Mac, Windows, iOS, Android). Siftbox stays in the background in Gmail, Outlook, or IMAP. Sources: sparkmailapp.com and Spark help base (August 2026). Verify the official site before you decide.

Comparison table

Sources verified in August 2026. Offers may change: check each publisher’s site.

  • Yes: criterion clearly covered per official sources.
  • Partial: limited feature, paid plan, or different experience.
  • No: criterion absent or explicitly out of scope.
  • N/A: criterion does not apply to this tool type.
Criterion Siftbox Spark Mail
No new mail client to install Yes No
Gmail, Outlook, and generic IMAP (OVH, host, etc.) Yes Partial
Readable classification reason per message Yes Partial
Explicit rule per sender Yes Partial
AI-drafted replies Yes via MCP Yes
External AI assistant connectable (MCP) (Claude, ChatGPT, Cursor) Yes No
IMAP with your usual client Yes Partial
Free plan available (indicative) Yes Yes
Read-only prioritization mode Yes N/A
  • Spark: you read and reply in the Spark app; IMAP and other accounts go through that client.
  • Siftbox: native IMAP (OVH, Infomaniak, private host, etc.) without changing mail client.
  • Spark +AI: drafts and summaries on Plus/Pro plans (sparkmailapp.com/pricing).
  • Siftbox: drafting via external assistant (MCP), no built-in inbox draft.
  • See the 4-tool comparison: /guides/comparatif-outils-triage-email

Spark Mail at a glance (source: sparkmailapp.com)

Spark is published by Readdle. You connect Gmail, Outlook, iCloud, IMAP, Yahoo, and others, and read mail in the Spark app. Smart Inbox separates priority, newsletters, and notifications. Spark +AI (Plus and Pro plans) uses Azure OpenAI to draft, summarize, translate, and power an AI Assistant. Free plan available; Plus at $10/month, Pro at $20/month ($8.25 and $16.58/month on annual billing, August 2026).

Spark Mail strengths

  • Free plan: Smart Inbox, unlimited accounts, calendar, smart notifications.
  • Unified multi-account interface, sync across Mac / Windows / iOS / Android.
  • Rich Spark +AI on Plus/Pro: drafting, summaries, translation, meeting notes (monthly quota).
  • Gatekeeper, Priority, Group by Sender, snooze, send later.
  • Team collaboration: shared drafts, comments, shared inboxes (paid tiers).

Limits or things to watch

  • You must use Spark as your mail client (not a simple invisible layer inside Gmail web).
  • Spark +AI is off by default and reserved for paid plans (limited preview on Free).
  • Core product focus: read, write, collaborate; not an explicit reason per message like Siftbox.
  • Data encrypted via Google Cloud (Spark); AI via Azure OpenAI: see their privacy page.
  • "Auto-Labels" and "Auto-Drafts" listed as "SOON" on the Pro plan (August 2026).

Gmail, Outlook, or generic IMAP?

Siftbox covers Gmail, Outlook / Microsoft 365, and native IMAP (OVH, Orange, SFR, private host, etc.): connect your address and your host’s servers; triage is read-only and folders appear on phone, computer, and tablet. Spark can link IMAP accounts, but you must read and reply in the Spark app, not Thunderbird or your usual webmail.

What you gain with Siftbox

  • You stay in Gmail, Outlook, or your usual IMAP client (Thunderbird, webmail, etc.).
  • Four categories with a reason per message, correctable in one click.
  • Sender rule: a supplier or recurring contact can always land in Important if you decide (a rule you create).
  • Drafting via MCP: connect Claude, ChatGPT, or Cursor to use your sorted mail (no built-in inbox draft).
  • Read-only; Europe-oriented hosting; see /trust.
  • Free beta with no card, then €14.99 incl. VAT / month / sorted email account (or €149 / year).

What about drafting? Each tool, its job

Spark +AI drafts inside the Spark app (paid plans). Siftbox does not draft in your inbox: it sorts and explains. If you need writing help, connect Claude, ChatGPT, or Cursor via MCP to rely on your already sorted mail, with your CRM and tools, without leaving your usual mail client.

Choose Spark Mail if…

  • You want a modern all-in-one mail client with AI drafting.
  • You need the built-in calendar, integrations (Notion, HubSpot, etc.), and team workflows in Spark.
  • You are ready to switch apps for daily mail.

Choose Siftbox if…

  • You want to keep your current inbox and client (Gmail web, Outlook, Thunderbird, etc.).
  • Your main need is to prioritize with explanations, not generate replies.
  • You refuse AI drafting on your behalf without relevant context about your work, processes, or clients, and want explicit sender rules.
  • You want to connect ChatGPT, Claude, or another assistant to your email.
Try Siftbox for free

Free beta · no new mail client · no credit card

Frequently asked questions

Yes, via Smart Inbox, Priority, and Gatekeeper. Siftbox goes further with a text reason per message and explicit correction in the Siftbox product.

In practice, both address different jobs (mail client vs layer). Most users choose one or the other.

No. Siftbox works in the background on the connected inbox. You keep opening mail in the client you already use.

Spark offers Spark +AI in its app. Siftbox does not draft in the inbox: after sign-up, connect Claude, ChatGPT, or Cursor via MCP (Settings → AI assistants). Guide: /guides/connecter-assistant-ia-siftbox.

Both can link IMAP. With Siftbox, you keep your usual mail client and triage is applied on the server. With Spark, you go through the Spark app to read and reply.