If you are not able to send or receive emails in your SmarterMail account, and you are receiving errors such as 'The domain size limit has been exceeded,' 'Email has exceeded the 1000MB Limit,' or 'This mailbox is full,' it means your email account has exceeded the space limit allotted and you will need to clear out your messages to free up your account.
You can adjust the quotas to allocate more space to the user whose mailbox is full (assuming you have free email disk space for your domain). See this Knowledge Base article for information on how to determine how much email disk space you have allotted to your domain's users.
The first step to clearing your messages is to see which users on the domain are using up the most space. To see this, you will need to login to your SmarterMail account under the Admin user. If you are not logged in as the Administrator, you will not be able to view all users on the account.
Note: You may login to check on your each of your user's mailbox size via domain administrator account
To delete emails:
1. Log into the SmarterMail email console for the email address.
2. Click on Email, then Inbox on the left menu.
3. Check the "Select" button listed at the top of the message interface
4. Select the emails you do not need.
5. Mouse over the Delete button and click Delete at the top of the message interface.
6. Go to your Sent Items folder (if you have one), and delete those items as well.
7. Finally, go to your Deleted Items folder and repeat the deletion process. The space will not free up until you have removed the emails from the Deleted Items folder.
Repeat this process for as many users as you have in the SmarterMail account with large amounts of stored mail.
To purchase purchase additional storage for mailbox, please see this Knowledge Base article.