Scenario
A user is unable to send or receive emails in Outlook. When attempting to send a message, they may see an error indicating that their mailbox is over its size limit.
Reason
This occurs when a mailbox reaches or exceeds the storage quota set by the email provider or organization. Mailbox limits help manage server resources, and once the quota is exceeded, sending or receiving emails is blocked until the mailbox size is reduced or the quota is increased.
Resolution
To resolve this issue and regain full email functionality, follow these steps:
- Check Mailbox Usage
In Classic Outlook, select File from the ribbon bar, select Tools, then select Mailbox Cleanup to view the total mailbox size and the size of individual folders. Clean Up Your Mailbox
Use the Mailbox Cleanup tool to locate and delete large or old emails.
Empty the Deleted Items and Junk Email folders by right-clicking each folder and selecting Empty Folder.
Archive Old Emails
Use the AutoArchive feature to move older emails to a separate PST file.
To configure, select File, then select Options, Advanced, then select AutoArchive Settings.Manage Attachments
Save attachments to your local drive or cloud storage, then remove them from the email to reduce mailbox size.
Request a Quota Increase
If mailbox limits are regularly reached despite cleanup efforts, contact your email administrator or service provider to request an increase in quota.