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Feb 28 2024 07:00 AM - Feb 29 2024 10:30 AM (PST)
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How to increase a mailbox size ?

Copper Contributor

Currently we have 50 GB of mailbox size available, and one of the mailbox has reached this limit! I have to urgently increase the size but can't find the way to do it.


Is it even possible??

10 Replies

Hi Alex,


To increase the size of mailbox you will need a plan that have more space like E3 or E5 with 100Gb Mailbox and Archive too.

Yes. Just in case, all EXO limits, includes mailboxes and arhives, are here

How come i can't have more then 100 GB in my mailbox? is it really a business solution, huh Microsoft?
what can i do if i need 300 GB and can't delete those emails at all?
One way to win extra space is just enable Archive feature in your MailBox so you will have 50 extra GB of storage

@Alex Orso

With E3 and E5 in theory you should get unlimited archiving, wich is the MS solution to your problem. Unfortunately though I think the ulimited archiving rollout has been paused.

Maybe @Tony Redmond can tell us what is the present situation. 

Salvatore - that's news, never heard about that. On the hand link in my previous post was updated only a week ago, no changes announced.


And that's interesting "unlimited" is only marketing trick and some actual limit exists (i know about the theoretical limit, but that's huge number) - afraid no one tested.

Exchange Online Plan 2 also has a 100GB limit.

Expandable archives were paused but my understanding is that the deployment is now complete or almost complete across all Office 365 datacenter regions.


The original question is what to do when a mailbox gets to 100 GB. Well, primary mailboxes do not have auto-expand capability, so when you get to 100 GB, your mailbox stops being able to accept new mail. That's the reason why running retention policies to remove or archive old content is a good idea. So the right answer is to archive-enable the large mailbox and apply a retention policy to remove old content and let MFA move the information for you.



I have only 14.85 GB