Microsoft 365 Mailbox capacities and sizes (2024)

FAQs

How much mailbox capacity does Microsoft 365 have? ›

You get 15 GB of free Outlook.com email storage which is separate from your Microsoft cloud storage. You have 5 GB of free cloud storage with your Microsoft account shared across your files and photos in OneDrive, attachments in Outlook.com and your Microsoft 365 apps. Microsoft 365 subscribers get 50 GB of space.

Maximum total message send/receive size is 150mb. This includes both the message content and attachments. Attaching a large file to an email message requires uploading that file to the email system. This can increase the time required to send the message.

Click the File tab. Click Tools > Mailbox Cleanup. Select View Mailbox Size, Find items older than, Find items larger than, View Deleted Items Size, Empty Deleted Items folder, View Conflicts Size, or Empty Conflicts to perform your desired task.

If your mailbox is nearing its maximum capacity, we will begin sending you emails and in-app messages telling you your storage is almost full. If it does exceed capacity, you won't be able to send or receive any messages.

You cannot have more the one primary email address per MS Account but you can create as many Microsoft/Outlook.com accounts as you want.

Email and calendars

Get business-class email with Outlook, including a 50 GB mailbox per user, and send attachments of up to 150 MB.

If you upgrade the plan to Enterprise E1, E3, and E5, the storage limit will automatically increase to 100 GB. To increase the mailbox size in Office 365 over 100 GB, follow the steps given below: Open the Microsoft 365 Admin Center. Select the Billing option.

Try to Empty Deleted Items Folder for that you've deleted emails, they might still be in the Deleted Items folder. Empty this folder to free up space. Check Other Outlook Folders for that ensure all other folders in Outlook (Sent Items, Drafts, Junk Email, etc.) are empty or have been cleared out.

What do I do when my Outlook mailbox is full? ›

The Office 365 mailbox size limit for the top subscription plan is 100 GB. As for archive mailboxes, Office 365 email storage limits are 50 GB for most subscription plans. High-end subscription plans include 1.5 TB of archive storage with auto-expanding capabilities.

The default size of Microsoft 365 mailboxes varies based on the mailbox type and user subscription. The default size of a user mailbox is either 50 GB or 100 GB, and when the space is exhausted, users won't be able to send or receive emails.

If a mail receptacle is deemed by the letter carrier to be full, the letter carrier will leave a "We ReDeliver for You" form (PS Form 3849) in that receptacle and return the overflow mail to the local Post Office™ location for pickup. The LPO will automatically hold accumulated mail for up to 10 days.

Click Mailboxes under Recipients. Double click the user that you want to edit and click mailbox features. Scroll down to Message Size Restrictions and click View details. Change the number in KB and then click OK.

As a Microsoft 365 Basic subscriber, you get 50 GB of free mailbox storage for your Outlook.com emails, contacts and calendar items. You also get 100 GB of free cloud storage for your email attachments, files and photos in OneDrive.

Exchange Online (Microsoft 365) – you need to enable auto-expanding archiving to increase the storage limit to up to 1.5 TB. According to Microsoft's documentation, it can take up to 30 days until additional storage space (another 100 GB) is provisioned for archive mailboxes in Exchange Online.

The default size of Microsoft 365 mailboxes varies based on the mailbox type and user subscription. The default size of a user mailbox is either 50 GB or 100 GB, and when the space is exhausted, users won't be able to send or receive emails. To avoid this, admins need to keep a check on the mailbox size.