Hey everyone! I've noticed that in our M365 setup, both user and shared mailboxes are capped at 20GB. I believe shared mailboxes can actually go up to 50GB without needing a license, and licensed users can have even larger mailboxes depending on their specific license. My question is, does your setup create 50GB mailboxes by default? Since we're in a hybrid configuration, I'm thinking this 20GB limit might be inherited from an older configuration. If we decide to expand all mailboxes to 50GB, what should I consider? We typically set Outlook to cached exchange mode but disable it for shared mailboxes. Just to clarify, I have no intention of allowing any mailbox to exceed 50GB. Thanks for your help!
4 Answers
I agree, really keep an eye on the shared mailboxes. Cached mode disabled helps a lot and usually 50GB is sufficient, just be cautious not to let them exceed that unless you're prepared for the feedback from users.
The size of the mailbox really depends on the user's role. For instance, office workers typically get 50GB because Outlook is their main tool, while field employees might only need the basic 2GB from the F3 license. It’s best to evaluate based on each user's role rather than a one-size-fits-all approach.
Just a heads up, for F3 users, make sure their primary device is under a 10" screen.
In our organization, our limits are 2GB for frontline workers, 50GB for shared mailboxes, and 100GB + 1.5TB archive for office users. We monitor shared mailboxes closely, and if any reach 45GB or the recoverable items hit 90GB, we reach out to the owner. If needed, we either license the mailbox and enable archiving or create a new mailbox. Our retention policy can complicate things since deleted items aren't purged easily, which is a hassle. We don't allow caching for shared mailboxes to maintain performance, especially in a large environment like ours.
To set the mailbox limit, you can use the following command: Get-Mailbox -ResultSize Unlimited | Set-Mailbox -ProhibitSendQuota 49GB -ProhibitSendReceiveQuota 50GB -IssueWarningQuota 45GB. For future mailbox plans, you could run: Get-MailboxPlan | Set-MailboxPlan -ProhibitSendQuota 49GB -ProhibitSendReceiveQuota 50GB -IssueWarningQuota 45GB.
Thanks for the tip, BrennanSB!