Mac email apps that cope well with several accounts

Most roundups of Mac email apps rank them by how the interface feels. That is a reasonable way to choose when there is one account. With four, the ranking collapses, because the feature that decides everything is buried in the pricing page rather than the feature list: how many accounts the app will actually accept before it asks for money.

The spread is wider than it looks. One well-known client allows a single account on its free tier. Another allows unlimited accounts at no cost at all. Between those two sits a $400 difference in five-year cost for the same job. Starting from the account limit rather than from the design narrows a field of ten apps to two or three in about a minute.

The number that decides it

Every app in this category has a free tier, and the free tiers are not comparable. Some cap accounts, some cap devices, some cap commercial use, and some cap nothing.

Checking that number first matters because it is the only limit that cannot be worked around. An interface that is slightly wrong can be lived with. An app that refuses the third account cannot.

App	Accounts on the free tier	Paid	Worth knowing
Apple Mail	Included with macOS, no published limit	None	Speaks IMAP, so Gmail labels arrive as folders
Thunderbird	Free forever, funded by donations	None	Unified inbox or separate account trees
Spark	Unlimited email accounts	Plus from $10 per user per month	Free plan includes Smart Inbox and notifications
Canary Mail	Unlimited mail accounts, 2 devices	Growth $3 per month billed yearly at $36	7-day trial, no credit card, downgrades to free
Mimestream	14-day trial, no credit card	$4.99 per month or $49.99 per year	Built for Google accounts, up to 5 devices
eM Client	2 accounts, personal non-commercial use only	$39.95 per year or $59.95 once, 3 devices	30-day trial and 30-day money-back guarantee
Mailbird	1 account per device	Unlimited on Premium, 3 devices per licence	Mac version requires macOS Ventura or later
Superhuman	None	Starter $25 per member per month, billed annually	Priced per member, aimed at teams

Figures are the published values on each vendor's own pricing page and change from time to time.

Two rows in that table should change most shortlists. Spark's free plan lists unlimited email accounts, and Canary Mail's free plan lists unlimited mail accounts as well. Multiple accounts is the headline paid feature across most of this category, so two products giving it away at the bottom tier is the single most useful fact here.

The ones built around one provider

Mimestream is the specialist. Its pricing page describes the subscription as covering all Google accounts, and the app is built on Gmail's own API rather than on IMAP. That means labels behave as labels, Gmail search syntax works as it does on the web, and category tabs are not lost in translation.

The trade is narrowness. Google accounts are what it is for. A hosting-provider IMAP account or a personal iCloud address has no place in it, so a mixed set of providers rules it out immediately. It is also sold directly rather than through the App Store, with the vendor citing pricing and group licensing as the reasons, and the app is still sandboxed, notarised and signed with an Apple Developer ID.

Apple Mail is the opposite kind of specialist: it is provider-neutral but protocol-bound. It speaks IMAP, and Gmail presents labels to IMAP clients as folders. A message with two labels therefore appears in two folders and in All Mail, so searching across three Gmail accounts returns a longer list than expected. Nothing is broken. The model underneath simply does not match.

Where cross-platform licensing changes the maths

Two apps in the table sell a licence rather than a subscription, and the terms differ in a way that matters for anyone with more than one machine.

eM Client's free licence allows 2 accounts and is limited to personal, non-commercial use. The Personal tier is $39.95 for a one-year subscription or $59.95 as a one-time payment, covering a single user with up to 3 devices, and the Business tier is $49.95 per year or $79.95 once, priced per device. There is a 30-day free trial and a 30-day money-back guarantee. For a freelancer, the non-commercial wording on the free tier is the detail to read carefully before relying on it.

Mailbird's free tier allows 1 email account per device, with Premium lifting that to unlimited accounts and 3 devices per licence. Its licence is explicitly cross-platform, valid on both Windows and macOS, which is unusual in this category and genuinely useful for anyone switching between a work PC and a personal Mac. The Mac build requires macOS Ventura or later, and the pricing page keeps separate Windows features and Mac features comparisons, which is a clear signal that the two builds are not identical. Anyone choosing it for a Mac should check the Mac column rather than the general feature list.

The free option with no vendor at all

Thunderbird belongs in a category of its own, because the money question does not apply to it. It is free forever, funded by user donations, and open source as part of the Mozilla family. Accounts can be kept in separate trees or collapsed into a unified inbox, and there is no account limit, no device limit and no commercial-use restriction to read.

The current Extended Support Release is Thunderbird 153, named Meadow, which builds on Thunderbird 140 Eclipse. The download page also offers a monthly Release channel, a Beta and a Daily build, and for a machine holding work accounts the Extended Support Release is the steadier choice.

One current development is worth knowing before dismissing it as the old option. Microsoft is disabling Exchange Web Services support on Microsoft 365, and Thunderbird has announced native support for the Microsoft Graph API specifically to keep that functionality working through the change. For anyone with a work Microsoft 365 mailbox alongside personal accounts, that puts Thunderbird in a better position than its reputation suggests, and it makes staying on a supported release channel the thing that matters rather than which app was chosen.

What it asks in return is tolerance for an interface that is configurable rather than opinionated. The settings are all there, which is the appeal and also the reason some people bounce off it in the first hour.

Five years of the same job

Subscription and licence pricing diverge slowly, and the account limit is what forces the choice, so it is worth seeing the shape of it.

A subscription at $49.99 per year, which is Mimestream's published annual price, comes to roughly $250 across five years. Canary Mail's Growth tier at $36 per year comes to about $180. A one-time eM Client Personal licence at $59.95 is paid once, though major version upgrades are sold separately. Thunderbird, Spark's free plan and Canary Mail's free plan are zero.

The point is not that cheaper wins. It is that the gap between the free options and the subscription options over five years is large enough to be worth thirty minutes of testing rather than a guess. Every paid app here has a trial, and the trials are generous: 14 days with no credit card for Mimestream, 7 days with no credit card for Canary Mail which then downgrades to the free plan automatically, and 30 days plus a money-back guarantee for eM Client. Running two candidates side by side for a week costs nothing and settles the question properly.

What a unified inbox does not fix

Every app here offers some form of combined view, and all of them stop at the same three places. Knowing this prevents choosing an app to solve a problem no app in the category solves.

Notifications come from the application. macOS identifies the app, not the account, so an alert says mail arrived without saying which of four mailboxes received it. Per-folder rules narrow what notifies at all, and a Focus filter can limit notifications to selected accounts, but the alert itself has no account identity.

Identity is the second. Replies leave from the account that received the message in every client here, which is correct. New messages leave from whichever account is selected in the From field, and in a merged view the correct one is no longer obvious. This is the most common way a message goes out under the wrong name, and no interface design removes it.

Search is the third. One list of everything means every search covers everything. That is the point of merging and also the cost of it.

The accounts that are not email

Email is usually the smaller half of the problem. The same person running four mail accounts is normally also running two Slack workspaces, two Notion logins and a Google Drive that keeps switching to the wrong profile. A mail client, however good, does nothing for those.

This is where the browser becomes the bottleneck. A browser profile holds one set of cookies per site, so a second account of the same service means logging out, or a second profile, or an incognito window that forgets everything on close.

An app aggregation browser for macOS handles this the way a mail client handles accounts. Each app gets its own cookie container, so several accounts of the same service stay signed in at once and none of them can see the others, and switching between them costs a keystroke rather than a login. The workspaces model is where the containers are described, and a side-by-side view against Wavebox covers how the category differs internally, since the free tiers here vary as much as the mail clients do.

Used together, the split is clean. The mail client owns mail. The browser owns everything else with a login.

Choosing in one pass

Four rules cover most situations without reading a single review.

If every account is a Google account, Mimestream is the strongest fit, because it works with Gmail's model instead of translating it. Budget for a subscription, since there is no one-time option.

If the providers are mixed and the budget is zero, Spark or Canary Mail on their free tiers, or Thunderbird. All three accept several accounts without payment, and Thunderbird adds no device limit at all.

If a licence is preferred over a subscription, eM Client or Mailbird. Check the commercial-use wording on eM Client's free tier and the Mac feature list on Mailbird before buying.

If the mail is already fine and the friction is everywhere else, do not change mail clients. The problem is session handling in the browser, and swapping mail apps will not touch it.

What to change first

Open the pricing page of whichever app is currently in use and find the account limit. If the current setup is already inside it, the mail client is not the problem, and the next place to look is the number of times a day a browser asks for a login it should already have. SpaceDeck is built for that second half, and it leaves the mail client alone.