All Inboxes Not Showing All Emails: How to Fix It
Put every mailbox on one board and let AI categorize and de-spam each message.
All Inboxes stops showing every message for one of five reasons: a category filter is hiding mail behind a tab, an account has been switched off, Mail is offline, the All Inboxes mailbox was removed from Favorites, or a server-side rule moved the message before it ever reached the Inbox folder. Each one has a different fix. The first is recent enough that most of the advice you will find online does not mention it, and it is now the most common cause by a wide margin.
What follows covers Mail on Mac, iPhone and iPad, then the equivalent problems in Outlook and Gmail, then the structural reason a combined inbox keeps breaking no matter which app you use.
Why is All Inboxes not showing all emails?
Start with the category filter, because it accounts for most of these reports since Apple added Categories to Mail. When categories are on, the inbox is split into Primary, Transactions, Updates and Promotions, and the view defaults to Primary. Mail that has been sorted into one of the other three is still there and still unread, but it is not on the screen you are looking at. It reads exactly like missing mail.
The fix is to turn the filter off rather than hunt through tabs. Click the selected category button at the top of the message list, and Mail switches back to showing everything in the inbox. On iPhone the same control sits at the top of the list. If you would rather not deal with categories at all, you can switch the whole view back to a plain list, and All Inboxes then behaves the way it did before.
Here is the short version of every cause, with what each one looks like from the outside.
| What you see | Actual cause | Fix |
|---|---|---|
| Some mail missing, unread counts look wrong | Category filter is showing Primary only | Click the category button to clear the filter, or turn categories off |
| One account's mail is entirely absent | That account is disabled in Mail settings | Mail, Settings, Accounts, check Enable this account |
| Nothing new arrives anywhere | Mail is offline | Mailbox menu, Take All Accounts Online |
| All Inboxes is gone from the sidebar | Removed from Favorites | Hover Favorites, click the plus, add All Inboxes back |
| All Inboxes is greyed out | Only one account is currently enabled | Re-enable a second account, or select On My Mac to refresh the list |
| Specific senders never appear | A server-side rule skips the inbox | Fix the filter on the provider, not in Mail |
Why did All Inboxes disappear from Mail on my Mac?
Two different things get described this way, and they have different fixes.
If the sidebar simply no longer lists All Inboxes, it has been removed from Favorites. Hover over the Favorites heading in the sidebar, click the plus that appears, and choose All Inboxes from the menu. It goes straight back to the top of the list. This happens after some upgrades and after anyone drags a mailbox out of the Favorites section by accident.
If All Inboxes is not merely hidden but genuinely unavailable, the cause is almost always that Mail can only see one active account. All Inboxes is a combined view, so it has nothing to combine when there is one inbox. Open Mail, then Settings, then Accounts, click each account in the left column and confirm that Enable this account is checked. An account can also be switched off outside Mail, in Internet Accounts in System Settings, where turning off the Mail toggle for an account removes it from Mail entirely without deleting anything.
Why is All Inboxes greyed out in Mac Mail?
Greyed out is the same single-account problem wearing a different hat, and the fix above resolves most cases. There is a second, stranger one worth knowing: several people have found that scrolling down the sidebar and clicking On My Mac forces Mail to rebuild the mailbox list, after which All Inboxes reappears in normal color. It looks like superstition and it is not: selecting a different mailbox source makes Mail re-evaluate which combined views are valid.
If neither works, check that Mail is actually online. The Mailbox menu has a Take All Accounts Online item, and if it is available rather than greyed, at least one account is offline. An offline account contributes nothing to the combined view, so All Inboxes can look broken when the real problem is a connection that dropped and never came back.
Why is All Inboxes not showing on my iPhone or iPad?
On iOS and iPadOS the mailbox list is editable, and All Inboxes can be unchecked. Open Mail, go back to the Mailboxes screen, tap Edit in the top corner, and confirm All Inboxes has a check next to it. This is the answer for most cases of All Inboxes disappearing on an iPad, because the Edit screen is easy to open by accident and the change syncs to nothing, so it looks arbitrary.
The other iOS-specific cause is an account that has Mail turned off. Go to Settings, find Mail, open Mail Accounts, tap the account, and check that the Mail toggle is on. An account with Mail switched off keeps its calendar and contacts syncing while its messages vanish from every view, which is why people so often conclude the mail itself was deleted.
If you are setting a phone up from scratch and want the combined view to work properly across accounts, the setup order matters more than it should. We walk through it in the guide to a unified inbox on iPhone.
Why does mail from Gmail never reach All Inboxes?
Because it never reached the Inbox folder. All Inboxes is a union of the Inbox folders of your enabled accounts, and nothing more. If a Gmail filter has Skip the Inbox turned on, the message is labeled and archived on Google's servers before any client sees it, so it is not in the Inbox folder for Mail to collect. The same is true of anything Gmail routed to Spam.
Fix this on the provider rather than in Mail. Open Gmail's filter settings on the web, look for filters that skip the inbox or apply a label instead of delivering, and decide which of them you actually want. It is worth doing once properly, because these filters accumulate over years and nobody remembers writing them. The related quirk, where Gmail's own multiple-inboxes feature splits your mail into panes that other clients cannot see, is covered in the piece on Gmail multiple inboxes.
All Inboxes vs All Mail: what is the difference?
All Inboxes shows only the Inbox folder of each enabled account, combined into one list. All Mail is broader: in Gmail it is the archive that holds every message you have not deleted or marked as spam, and in Apple Mail there is a separate All Mail smart mailbox that unions every mailbox of every account, including Sent, Drafts, Archive and custom folders.
The practical consequence is that a message you archived is in All Mail and not in All Inboxes, which is correct behavior rather than a bug. If you are looking for something you know arrived and cannot find it in the combined inbox, look in All Mail before assuming anything is broken. The distinction between a combined inbox and a genuinely unified view of everything is a real one, and we pulled it apart in unified inbox vs combined inbox.
Does Outlook have an All Inboxes view?
Not in the way Apple Mail does. Outlook on the desktop keeps each account in its own folder tree, and the usual workarounds are a Search Folder scoped across accounts or adding several inboxes to Favorites so they sit next to each other. Neither produces a single sorted list, and both stop working the moment you add another account. The full set of options, including what Outlook genuinely cannot do, is in our guide to a unified inbox in Outlook.
What actually gets lost when the combined view breaks
It is worth being specific, because the answer explains why people spend an afternoon on this. In a broken combined inbox the messages that go unnoticed are rarely the ones you would miss immediately. They are the second-tier ones with deadlines attached: a client reply that landed in the account you check least, a renewal notice, a bill that needed approving before it went late. Anything that arrives on a schedule and needs a small action tends to sit in whichever account fell out of the view. Finance teams solve part of this by taking the payables out of email entirely and having vendor bills routed into an approval workflow instead of sitting in someone's inbox waiting to be spotted.
The rest of it is a structural problem with the view itself. All Inboxes, Unified Folders in Thunderbird, and Favorites in Outlook are all the same idea: stack the inbox folders on top of each other and present them as one list. That merges the queues but does nothing about the contents, so the combined view is simply a bigger undifferentiated pile, and one misconfigured account silently removes a whole stream of mail from it without telling you.
How do you stop the combined inbox from breaking?
Two things help. First, stop relying on per-device configuration. Every cause listed above is a setting on one machine: an account disabled here, a mailbox unchecked there, a filter written on the web years ago. Each device holds its own copy of that configuration, so a fix on your Mac does nothing for your phone and the two views drift apart.
Second, make the combined view do more than stack folders. If every message that arrives at any of your accounts is read and given a category as it lands, an account that stops delivering is obvious, because its stream of categorized mail simply stops. That is the approach behind putting all email accounts in one place on a single board that lives on the server rather than on each device: connect the mailboxes once, and the same sorted view opens in any browser, on any machine, with no per-device settings to drift.
If you have been maintaining the same fragile combined view across three devices for years, the honest fix is not another settings walkthrough. It is to combine your email accounts somewhere the configuration only exists once.