What is the maximum mailbox size in Google Workspace?

There is no per-mailbox maximum. The mailbox is bounded only by the tenant's pooled storage, which is 30 GB per user on Business Starter, 2 TB on Business Standard and 5 TB on Business Plus.

What happens when Google Workspace storage is full?

Sending continues, receiving stops, and Drive becomes read-only. Outside senders get bounces while internal users often notice nothing, which is why it is frequently reported as a mail fault.

Does suspending a user free up storage?

No. Suspension keeps all data and its storage consumption. Space is released only when the data is transferred elsewhere and the account's data is removed.

Is there a cheaper licence for a leaver's mailbox?

Yes, an Archived User licence retains the mailbox and its Vault coverage without an active seat. It saves licence cost, not storage, because the data still counts against the pool.

Reference

Google Workspace mailbox size and storage limits

Name: Workspace Migration Services
Address: 5th Floor, 5 Conduit Street, London, W1S 2XD, GB
Telephone: +44 20 7183 3436

Google Workspace sets no per-mailbox size limit. Storage is pooled across the tenant at 30 GB per user on Business Starter, 2 TB on Business Standard and 5 TB on Business Plus, so a single mailbox can consume the entire pool. When the pool is exhausted, sending continues and receiving stops.

Pooled storage by edition
Business Starter	30 GB per user, pooled
Business Standard	2 TB per user, pooled
Business Plus	5 TB per user, pooled
Enterprise Standard and Plus	5 TB per user, pooled, more on request
Per-mailbox cap	None; a mailbox may consume the whole pool
At exhaustion	Sending continues, receiving stops

Pooled, not per user

Google multiplies the per-user allowance by the licence count and gives the tenant a single pool. Mail, Drive, shared drives and Photos all draw from it. Nobody has a personal quota, which is why the admin console shows storage by account as consumption rather than as a limit.

The practical consequence is that adding seats adds storage, and removing seats removes it. A tenant close to its pool ceiling that reduces headcount can find itself over the line without anyone uploading anything.

What happens when the pool runs out

Sending keeps working. Receiving stops, new files cannot be created, and Drive becomes read-only. This asymmetry is why storage exhaustion is often reported as a mail delivery fault: the people inside the organisation notice nothing unusual, while senders outside receive bounces.

The recovery order matters. Emptying trash releases space immediately, archived mail does not release any, and deleting a user only releases their consumption once their data is transferred or removed rather than at suspension.

Check shared drives before mailboxes; they are usually larger
Look for service accounts collecting scanner, CCTV or export output
Trash counts against the pool until it is emptied
Suspending an account does not release its storage
Buying additional storage is possible on some editions instead of moving edition

Archived User licences and leavers

A leaver whose mail must be retained does not need a full licence. Google offers a cheaper Archived User licence that preserves the mailbox and its Vault coverage without an active seat, which is the correct answer for a departed employee under a retention obligation.

Storage still counts against the pool, so archiving is a licence saving rather than a storage saving. Organisations that need the storage back have to make a retention decision, not a licensing one.

What we see that others don't say

Because the pool is shared, the account that exhausts a tenant's storage is rarely a person. It is usually a service account collecting scanner output or backup exports, holding several hundred gigabytes nobody has looked at since the year it was configured.

What this doesn't cover

Education, Nonprofit and Frontline editions carry different storage allowances that are not listed here.
Google changes allowances and additional-storage availability without notice; verify against the linked Admin Help article before designing around a number.
Individual and personal Google account limits are different from Workspace tenant limits and are out of scope.

Want this done for you?

Three fields. We come back with whether this is a 20-minute fix or a project, and what it costs.

Prefer to talk? Call +44 20 7183 3436 (Mon–Fri 08:00–18:00 GMT), or message WhatsApp +44 7403 423563.

Questions we get asked

What is the maximum mailbox size in Google Workspace?: There is no per-mailbox maximum. The mailbox is bounded only by the tenant's pooled storage, which is 30 GB per user on Business Starter, 2 TB on Business Standard and 5 TB on Business Plus.
What happens when Google Workspace storage is full?: Sending continues, receiving stops, and Drive becomes read-only. Outside senders get bounces while internal users often notice nothing, which is why it is frequently reported as a mail fault.
Does suspending a user free up storage?: No. Suspension keeps all data and its storage consumption. Space is released only when the data is transferred elsewhere and the account's data is removed.
Is there a cheaper licence for a leaver's mailbox?: Yes, an Archived User licence retains the mailbox and its Vault coverage without an active seat. It saves licence cost, not storage, because the data still counts against the pool.

How this page is verified

Reviewed by Deepak Shukla, Founder, Workspace Migration Services. Last checked 2026-09-19.

Per-edition storage allowances reflect Google Workspace Admin Help storage documentation as of 2026-09-19.
Exhaustion behaviour reflects Google Admin Help guidance on storage limits as of 2026-09-19.
Service-account observation derives from Workspace Migration Services tenant audits to 2026-09-19.

Sources you can check

Pool nearly full?

Send your edition and seat count. We will tell you whether the answer is a clean-up, extra storage, or an edition move, and what each one costs.

Book an audit See pricing