Mimestream vs Spark for Gmail on a Mac

Pick Mimestream if every account you have is Gmail, you work on a Mac, and you want an app that talks to Google directly and keeps your data on your device. Pick Spark if you also have iCloud, Outlook or Yahoo mail, need the same app on iPhone, Windows or Android, or want a free plan.

The two apps answer different questions. Mimestream is a Mac app built only for Google accounts. Spark is a free, cross-platform client for almost any provider, with paid AI and team features on top. The facts below come from each vendor's own pages, as of November 2026.

Mimestream and Spark at a glance

Alrighty is our app. It's in the first column as a third option, and it has its own section further down.

	Alrighty	Mimestream	Spark
Runs on	Mac (Apple silicon), Windows, Linux	Mac (macOS 12 or later); iPhone and iPad in beta	Mac, iPhone, Windows, Android
Accounts	iCloud, Gmail, Outlook	Google accounts only	Gmail, Outlook, iCloud, Yahoo, AOL, GMX, IMAP
Price	14-day trial, then Free plan or Pro	$4.99 a month or $49.99 a year, after a 14-day trial	Free; Plus $99 a year; Pro $199 a year
Where mail is kept	Your computer, searched on your computer	Your device; search runs on Gmail's servers	Your provider; some features run on Spark's servers
Unwanted mail	Stop mail, Clean up, Filters	Tracker blocking, Gmail filters and categories	Gatekeeper screens new senders; block sender or domain
AI, and its default	Reply drafts start when you open a reply, signed in; your own AI is off until you connect it	Apple's Writing Tools only	Spark +AI on paid plans; free plan gets a preview

Which is better for Gmail, Mimestream or Spark?

Mimestream is the closer fit for a Gmail-only user. Its home page lists "Full support for Gmail labels, including color-coding and visibility settings," lets you manage "your server-side Gmail filters," and lets you send from "any Gmail Alias configured in your account." It also shows Gmail's inbox categories, so promotions stay out of Primary.

That depth comes from how it connects. Mimestream says "the app establishes direct connections to the Gmail API, without going through any intermediary sync service." Spark treats Gmail as one provider among many. Its Mac App Store listing names "Gmail, Microsoft Outlook, AOL, Yahoo, Hotmail, IMAP, GMX, and iCloud" in one unified inbox (App Store). Spark's pages don't describe Gmail labels, filters or aliases, so we make no claim about how well it handles them.

If Gmail is your only mail, Mimestream gives you more of Gmail. If Gmail is one of several accounts, Mimestream can't hold the others.

Is Mimestream or Spark cheaper?

Spark is cheaper if its free plan covers what you need. Free includes "Smart Inbox," "unlimited email accounts," Smart Notifications and a calendar (Spark pricing). Mimestream has no free plan.

The paid tiers compare like this:

• Mimestream: $4.99 a month or $49.99 a year, per person or per seat for teams. The pricing page offers a "fully functional 14-day free trial that doesn't require a credit card." A license works on up to 5 devices, and you can share it with family in your household. Annual plans get a full refund within 30 days. Monthly plans get no refund, but you can cancel any time.
• Spark Plus: $10 a month or $99 a year. It adds Spark +AI, the AI Assistant, 40 AI meeting notes a month, team features and templates.
• Spark Pro: $20 a month or $199 a year. It adds unlimited meeting notes, Autopilot, Auto-Drafts and read statuses.

Spark offers "a seven-day free trial for both Plus and Pro when you subscribe directly in the app." One Spark subscription unlocks paid features on every device where you use Spark. The Mac App Store also still lists a "Spark Premium" purchase at $7.99 and $59.99, a plan the pricing page no longer shows.

You buy Mimestream from Mimestream, not the App Store: the pricing page says "we have decided to initially focus on direct sales only."

Which keeps your mail off its servers?

Mimestream does. It says it "only stores your data and tokens on your device," and it has no sync service in the middle (Mimestream).

Spark runs some features on its own servers, and it says so on its privacy page:

• Teams, shared emails and comments, shared drafts, delegation, templates and Send Later "require our server-side email processing to work."
• For push notifications, Spark "syncs the subject and a part of your message, encrypts this information and stores it," and deletes it 4 hours after the notification.
• For Gmail, Spark stores "an application-specific token," not your password. For iCloud it asks for an app-specific password.
• Its servers are "hosted by Google in the US."

Spark also says your mail itself "is stored on the server of your email account." So the gap is narrower than it sounds: Spark holds a token and short-lived copies for its features, not your mailbox. But if you want no company between your Mac and Google, Mimestream is the one built that way.

Can you use Mimestream or Spark on iPhone and Windows?

Spark runs on Mac, iPhone, Windows and Android today. Mimestream is a Mac app that "Requires macOS 12 Monterey or newer," and its home page says "Mimestream for iPhone and iPad is in beta." Neither vendor offers a web app on the pages we read.

If you read mail on an Android phone or a Windows PC at work, Spark is the only one of the two that follows you there.

Does Mimestream or Spark have AI?

Spark has far more AI, and most of it is paid. Its AI help pages list compose, translate, summaries, "My Writing Style," meeting notes, the AI Assistant, Auto-Drafts and Autopilot. The free plan gets a "limited free preview." Spark +AI runs on "the Azure OpenAI Service," which "will not retain the data for more than 30 days" and "does not use this data to train models" (Spark). Spark's pages don't say whether its AI is on or off when you install the app.

Mimestream's AI is Apple's. Version 1.5.0 added "Mimestream's first integration with Apple Intelligence," with Writing Tools to "Proofread, rewrite, and change tone" (release notes). Its home page names no other AI feature.

Which has better search?

Mimestream uses Google's search: "the full power of Gmail-backed search" (Mimestream). Results come from Gmail's servers, so they match what you'd find on gmail.com. Spark's pages make no search claim beyond its paid AI Assistant, which can "Find, summarize, and take action on anything in your inbox."

Where Alrighty fits

Alrighty is for the Gmail user who also has an iCloud or Outlook account and wants one app for all three. It signs in to Gmail with Google and reads mail through the Gmail API, like Mimestream, and it adds iCloud and Outlook in the same inbox.

What it does that neither app above describes:

• Stop mail. One action unsubscribes from a sender every way the message offers, archives their mail, and moves their new mail out as it arrives. Clean up lists the senders you likely don't want, so you can stop them all at once.
• Search on your computer. It matches what you mean as well as the words, across every account: "when is my flight" finds the airline's confirmation. Mimestream sends each search to Gmail.
• Your own AI. Claude, ChatGPT's desktop app, Codex or a local model can read your mail once you turn it on with Connect AI, and work in a window you watch. Nothing sends until you click Send.

What to know. Alrighty runs on Mac, Windows and Linux. It takes iCloud, Gmail and Outlook only, so no Yahoo or other IMAP accounts, and it has no iPhone app or calendar. Signed in, opening a reply starts a suggested draft by itself, and Clean up sorts senders in the background. Both send the emails they read through Alrighty's server to AI model companies, OpenAI among them. It's a new app with a short track record. The price is a 14-day trial with no card, then a Free plan or Pro.

Which should you pick

• Gmail plus iCloud or Outlook, on a Mac, with fewer unwanted senders: Alrighty.
• Gmail only, on a Mac, with labels, filters and aliases done the Gmail way: Mimestream.
• Any provider, with apps for iPhone and Android too, or a free plan: Spark.
• AI meeting notes, auto-drafts or shared inboxes for a team: Spark Plus or Pro.
• No company in the path between your Mac and Google: Mimestream.

For more choices, see our Mimestream alternatives and Spark alternatives, or our pick of Gmail apps for Mac. Every comparison is on our compare page.

Questions

Can I move from Spark to Mimestream without losing mail?

Yes, if your mail is in Gmail. Both apps read your mail from Google, and Spark says your email "is stored on the server of your email account," so Mimestream shows the same mailbox once you sign in. Spark-only items, such as shared drafts and comments, live on Spark's servers and don't move.

Does Mimestream have a free plan like Spark?

No. Mimestream has a 14-day trial with no card, then $4.99 a month or $49.99 a year. Spark has a free plan with unlimited accounts.

Is Spark safe to use with Gmail?

Spark says that for Gmail it stores an application-specific token, not your password, and that it encrypts the data its servers hold. Its features such as Send Later and push notifications pass parts of your mail through servers hosted by Google in the US. Read its privacy page and decide if that suits you.

Does Mimestream work with Google Workspace accounts?

Mimestream's pricing page says the Individual plan covers "All your Google accounts," and a 2023 release note describes an integration with the Google Workspace Directory. It doesn't name Workspace on its home page, so check with Mimestream if your company's admin limits third-party apps.