Overview

Spark combines a Smart Inbox that separates priority mail from other messages with a unified inbox for multiple accounts. It supports IMAP, iCloud, Exchange, Outlook, Yahoo, and Google accounts, so it can organize existing email across providers rather than require a new address. Offline access, scheduled sending, and calendar tools round out its core capabilities.

The free plan is unusually capable for a multi-account workflow: it includes unlimited email accounts, Smart Inbox, Smart Notifications, essential email productivity features, and Calendar. The main reasons to pay are AI, richer team collaboration, and plan-specific additions—not a basic account-count ceiling.

Key features

Smart Inbox is useful for readers whose main problem is distinguishing urgent or important mail from everything else. Unified inbox support makes it practical to bring personal and work accounts together, while offline access and scheduled sending support common email routines. Calendar tools are included even on Free.

Team collaboration goes beyond simply sharing an email. Spark supports real-time work with private comments, shared information, delegated ownership, progress tracking, and deadlines. Plus includes essential collaboration; Pro adds advanced collaboration. That makes paid Spark more relevant to teams coordinating email-related work, though an individual who only wants better sorting may not need those upgrades.

Spark +AI can translate, summarize, draft, and proofread email. AI Assistant can find and summarize emails, attachments, meeting notes, and events, and take action on them. AI is disabled by default, and monthly quotas vary by plan, so buyers should not assume unrestricted AI use. Plus includes 40 AI Meeting Notes, while Pro includes unlimited AI Meeting Notes.

Integrations include Asana, Evernote, Google Drive, Microsoft Teams, Notion, Slack, Todoist, Trello, and Zoom, with availability varying by platform. This can connect email workflows to other work tools, but users should check that the integrations they depend on are available on their device.

Spark says it uses Google Cloud for data storage and encryption, uses TLS for server connections, and encrypts server databases. It also says user data is used for product optimization and is not shared with third parties; certain notification content is deleted from servers four hours after sending.

Pricing

Spark uses a freemium model. The Free plan costs 0.00 USD per free and includes Smart Inbox, unlimited email accounts, Smart Notifications, essential email productivity, and Calendar. It is the sensible starting point for individuals who want organization without paying, though it does not include the paid plans' stated AI and collaboration additions.

Plus costs 10.00 USD per month, billed $10 / month per user; $120 / year. It adds 40 AI Meeting Notes, Spark +AI, AI Assistant, essential team collaboration, custom templates, and productivity integrations. This fits individuals or small teams who need AI and core collaboration, but the per-user price scales with seats and AI use is quota-based.

Pro costs 20.00 USD per month, billed $20 / month per user; $240 / year. It adds unlimited AI Meeting Notes, Read Statuses, advanced team collaboration, HubSpot integration, and Spark CLI with triage access. It is the stronger fit for teams that need the higher collaboration tier or the added workflow tools; those who only need a unified inbox are better served by Free or Plus.

Enterprise has custom pricing and includes Security & Controls, a Dedicated Success Manager, and 1:1 Productivity Coaching. It is aimed at organizations that need those services rather than a per-user self-serve plan. Spark offers a seven-day free trial of Plus and Pro when subscribed to directly in the app. Support varies by plan, from self-service to priority support and a dedicated customer success manager.

Platforms

Spark is available on Android, iOS, macOS, and Windows. Integration availability varies by platform, so cross-device users should confirm that a particular integration is supported where they work.

Who it's for

Spark is a good choice for people juggling several email accounts who want priority messages separated from the rest, along with calendar and productivity tools. It also suits teams that want to coordinate email through comments, delegation, progress tracking, and deadlines. It is less compelling for someone seeking only a basic email client or expecting unlimited AI use at the entry paid tier.

Pros and cons

Pro: Free supports unlimited email accounts and includes Smart Inbox, notifications, and Calendar, making it useful without a subscription.
Pro: Team tools include delegation, comments, progress tracking, and deadlines, giving collaboration a clear role beyond shared access.
Pro: Paid plans combine email AI and meeting notes with distinct Plus and Pro collaboration tiers.
Con: Plus and Pro prices are per user, so team costs rise with each seat.
Con: AI is off by default and subject to plan-based monthly quotas, which limits predictability for frequent users.
Con: Integrations vary by platform, which may matter to people relying on a particular connection across devices.

Alternatives

For a broader directory of options, browse Email clients.

Mozilla Thunderbird is a free, open-source alternative with email, calendar, contacts, and multiple-account support across Android, Linux, macOS, and Windows. Choose it if open-source software and a free plan matter more than Spark's stated team and AI features.
Zoho Mail is worth considering for a small organization that can work within its free allowance of five users, one domain, and 5 GB mail storage per user.
eM Client may suit someone who needs a free option limited to two email accounts on one device.
Newton Mail is another freemium email option for readers comparing multi-platform clients.
Spike is an alternative for readers comparing team-oriented email plans.
Canary Mail offers a free plan with core inbox features and a seven-day period with paid features at no cost.
Mailbutler Smart Assistant is another freemium option to consider when comparing email assistants.
Airmail is limited to iOS and macOS, making it an option for readers focused on those platforms.

Verdict

Choose Spark Mail if you want to bring multiple accounts together, prioritize important messages, and have the option to add calendar, AI, and team workflows in the same app. Its free plan is a strong fit for a capable multi-account inbox; Plus and Pro make more sense when their per-user collaboration and AI additions justify the cost. Look elsewhere if open-source software is the priority or if you need AI without plan-based quotas.

	Spark Mail	Sylpheed
Free plan	Yes	No
Free trial	Yes	No
Paid from	$8.25/mo	—
Open source	No	No
Platforms	Android, iOS, macOS, Windows	Windows, macOS, Linux
Free plan	Yes	Yes
Paid from	$8.25/user/mo	—
Unified inbox	Yes	—
Offline access	Yes	Yes
Scheduled sending	Yes	—
Calendar tools	Yes	—
App coverage	—	desktop

Spark Mail vs Sylpheed

Spark Mail

Sylpheed