Several Gmail accounts in Apple Mail, and the catch

Adding three Gmail accounts to Apple Mail takes about five minutes. The accounts appear in the sidebar, All Inboxes shows everything in one list, and the constant switching between browser tabs stops. That part works.

The friction arrives later, and it is specific. Archiving does something different from what it did in Gmail. A reply leaves from the wrong address. A notification says there is new mail without saying which of the three accounts received it. None of these are bugs. They are the places where Gmail's model and the IMAP model that Apple Mail speaks do not line up, and knowing them in advance decides whether Apple Mail is the right container for all three accounts or only for some of them.

Adding the accounts

On macOS Ventura and later, the path is System Settings, then Internet Accounts, then Google. Mail can also do it directly through Mail, Add Account, Google. Either way the sign in happens in a Google window using OAuth, which matters for two reasons. Two step verification works normally, and no app specific password is needed, unlike the older approach of typing an account password into a mail client.

After sign in, macOS asks which services to enable for that account: Mail, Contacts, Calendars, and Notes. Enabling only Mail is a reasonable default when the calendar for that account is already handled elsewhere, and it keeps three sets of contacts from merging into one address book.

One detail is worth deciding at this point rather than later. The order the accounts are added becomes the order they appear in the sidebar, and that order is easy to change by dragging but rarely gets changed once work has started. Putting the account with the most traffic at the top costs nothing now and saves a small amount of scrolling every day afterwards.

Repeat for each account. There is no documented limit on how many Google accounts can be added, and the practical ceiling comes from something else, which is that each account downloads its own copy of the mail. A large archive on three accounts is a large amount of local storage. Mail, Settings, Accounts, Account Information has a Download Attachments option set to All, Recent, or None, and setting it to Recent on the low priority accounts is the usual fix.

What the unified inbox actually merges

All Inboxes is a view, not a mailbox. It stacks the inboxes of every enabled account into one chronological list, and each message keeps its account underneath. That distinction explains a few behaviours that look inconsistent at first.

Replying to a message sends from the account that received it. This is correct by default and is the main reason a unified inbox is safer for identity than a browser with three accounts stacked in one switcher.

Composing a new message uses whichever outgoing account is selected in the From field, and the default is set in Mail, Settings, Composing. The From field on a new message is the single most common source of a reply going out under the wrong identity in this setup.

One thing All Inboxes does not carry across is Gmail's category tabs. Primary, Social, Promotions and the rest are a feature of the Gmail interface, so a client sees the whole inbox as one stream. An account that relies on those tabs to stay readable will look considerably busier in Apple Mail than it did on the web. The usual remedy is a server side filter in Gmail that skips the inbox for the noisy senders, since that filter is respected by every client.

Smart Mailboxes can filter across accounts, so a single view of everything unread from two of three accounts is straightforward to build. VIPs also work across accounts, which is the closest thing Apple Mail has to per sender priority.

Where Gmail and IMAP disagree

Gmail is built on labels. One message can carry several labels and lives in All Mail regardless. IMAP is built on folders, where a message is in exactly one place. Apple Mail speaks IMAP, so Gmail presents its labels as folders and the mismatch shows up in three places.

The first is duplication. A message with two labels appears in two folders, and it is also in All Mail. Search results can therefore show what looks like the same message more than once. Nothing is wrong, but a search across three accounts produces a longer list than expected.

The second is deleting versus archiving. In Gmail, archive means remove the Inbox label while keeping the message. In IMAP, delete means move to Trash. What Apple Mail's delete key does on a Gmail account depends on the IMAP options in Gmail's own settings, under Forwarding and POP/IMAP, where the behaviour when a message is marked as deleted can be set to archive, trash, or immediately delete. Setting this deliberately, on each account, prevents the most alarming version of the problem, which is mail disappearing from a client that was expected to archive it.

The third is Mailbox Behaviours. In Mail, Settings, Accounts, Mailbox Behaviours, each account maps its Drafts, Sent, Junk, and Trash to a server folder. Left unset, drafts can end up saved locally rather than in Gmail's Drafts, which means a draft started on the Mac is not visible on the phone. Checking this once per account is worth the minute it takes.

Sending from the right address

Each Google account added to Mail brings its own outgoing server, so three accounts means three SMTP entries. That part is automatic.

Aliases are not. An address configured in Gmail under Send mail as does not appear in Apple Mail until it is added there too, in Mail, Settings, Accounts, Account Information, by editing the email address list for that account. Once added, it shows up in the From menu and sends through the parent account's server.

There is a second requirement that is easy to miss. The alias must already be verified inside Gmail. Apple Mail will offer the address as soon as it is typed into the list, but Google rejects mail from an unverified alias, so the message fails at send time rather than at setup time.

Notifications are per application, with one exception

macOS notifies per application. Apple Mail is one application holding three accounts, so a banner saying new mail arrived carries Mail's name and icon, not the account's. Mail, Settings, General limits which messages notify at all, with the choice of Inbox Only, VIPs, Contacts, or All Mailboxes, but that setting applies to the whole application rather than to one account.

The exception is Focus filters. A Focus mode on macOS can include a filter for Mail that limits notifications to selected accounts, so a work Focus can silence a personal Gmail account without silencing Mail entirely. This is a real answer for the common case of two accounts with different working hours.

What it does not do is give each account its own identity at the system level. The badge on the Dock icon is a single number across all three accounts. The notification looks the same whichever account it came from. Anyone whose problem is not a schedule but a hierarchy, where one client must interrupt and another must not, is asking for something that a single application containing three accounts cannot express. A container that macOS sees as a separate application is the shape that can, which is what Workspaces describes.

Search, offline access, and rules

Three accounts in one client changes how mail is found, and the change goes in both directions.

Search improves in one respect. Spotlight indexes what Apple Mail has downloaded, so a search covers all three accounts at once and works with the Mac offline. Anyone who has spent a year opening three browser tabs to look for one attachment notices this immediately.

Search also gets worse in another respect. Gmail's operators, the ones that make searching by label, by size, by has attachment, or by older than useful, do not exist in Apple Mail's search field. Mail has its own filters and its own syntax, and results are limited to what has been downloaded. An account set to keep only recent messages locally will return less than the same query run in Gmail on the web.

Rules are the same story. Apple Mail's rules run on the Mac and only while the Mac is awake and Mail is open. Gmail's filters run on the server, all the time, for every device. Filing and labelling belong on the server, and Apple Mail rules are best kept for things that are genuinely local, such as playing a sound or moving a message into a local mailbox for a project that lives on that machine.

The practical result is that Apple Mail becomes the place mail is read and answered, while Gmail on the web stays the place mail is organised. That split is workable, but it should be a decision rather than a surprise, because it determines which of the two is worth keeping open.

What stays outside Apple Mail

Mail carries the mail. The rest of the account stays where it was.

	Apple Mail	Gmail in a browser tab	One window per account
All accounts in one list	Yes	No	No
Reply uses the receiving account	Yes	Not always	Yes
Labels and filters editable	No	Yes	Yes
Snooze and Gmail search operators	No	Yes	Yes
Drive and Calendar in the same place	No	Yes	Yes
Own Dock icon and badge per account	No	No	Yes
Notifications separable by account	By Focus only	No	Yes

Server side filters and labels keep running whether or not Apple Mail knows about them, but editing them means going back to the Gmail web interface. Snooze, the Gmail specific search operators, and the category tabs are all absent. Google Workspace administrators can also restrict which clients may connect, so on a managed account the decision may not be the user's to make.

The wider point is that mail was never the only thing arriving. A working day on three Google accounts usually also involves three sets of Drive files, three calendars, and a Slack workspace or two. Apple Mail solves the mail problem cleanly and leaves the rest in browser tabs. For anyone comparing the tools that take the other approach, keeping every web app in a window of its own, the differences in supported services and pricing are set out in Compared with Shift, and the services already configured to run that way are listed on Supported apps.

What to change first

Set the IMAP deletion behaviour and Mailbox Behaviours on each Gmail account before moving any real work into Apple Mail, because those two settings decide where mail goes when the delete key is pressed. Then add any verified aliases to the account's email address list, so the From menu offers the right identity instead of the default one. If the remaining problem is that all three accounts still notify with the same name and the same badge, that is the part Apple Mail is not built to solve, and a SpaceDeck style window per account is the arrangement that separates it.