Fix Thunderbird Error: Can’t receive emails when the Inbox is full

Yash Sinha
Yash Sinha linkedin | Updated On - May 10, 2023 |

Read time: 4 minutes

Mozilla Thunderbird is an open-source application that originated as an offshoot of the Mozilla Firefox project. It is a cross-platform email client loaded with great features such as message management, junk filtering, extensions and themes, big file linking, etc. This application can customize your email experience, ensuring security. In addition, it also provides a quick filter option where users can instantly filter their emails. With suitable add-ons, one can also export Thunderbird emails. Despite its innovative features, users face issues while reading, sending, and receiving emails when the Thunderbird Inbox becomes full.

Reasons behind the issue

The user receives an error message when their Thunderbird Inbox is full. There might be various reasons behind this case; we have listed all the possible reasons below:

  • The recipient’s Inbox has many emails, and the server is not accepting anymore.
  • Users have multiple Thunderbird accounts that have not been cleaned over the years.
  • Thunderbird mailbox can store the mail up to 4GB only.
  • The issues with Thunderbird and Windows operating system.
  • Antivirus or firewall has deleted or isolated storage files.
Methods to resolve Thunderbird Inbox full cannot receive email

To resolve this problem, there are two methods available; they are listed below:

  • Compacting
    Whenever a user deletes mails from Thunderbird, it is not permanently deleted from the Mozilla Thunderbird. It is only marked erased or removed from the mail file. If a user wants to delete it permanently, they need to compact the folders. It is a mandatory task as multiple problems may face if the user doesn’t perform this activity on a daily or weekly basis. Here, the problem may occur due to increasing emails continuously. It’s a good practice if you perform this task daily for all the mailing programs, but it can also be done on a weekly basis for your convenience.
  • Deleting emails
    Most users reinstall the Thunderbird application to resolve the error, but the problem remains the same. The reason behind the error is related to the emails; hence, reinstalling the Thunderbird application will not be useful. You also have another option available to resolve the problem, i.e., delete unwanted and suspicious emails. For this, you can move the emails to another folder in the local hierarchy. The selected mails can also be moved in bulk at the same time. To perform this action, select all your emails using the shift key and then drag them into a new folder.

In most cases, you will see the results after moving or deleting emails.
Instead of deleting the file, you have another option, i.e., renaming the file. It can get your email into flow once again.
Note: In Explorer, you can see that each file is attached with a similar file. These files are the index files with MSF extension, which should be deleted after deleting or changing the file’s name. Otherwise, a new index will be generated by Thunderbird to keep the indexing issues away.

Change Deleted Items Settings

To change the Deleted Item settings, you need to follow the below steps:

  • Click on Menu -> Account settings.Click on Menu Account settings
  • Next, click on Server on Server Settings
  • Navigate to the Leave messages on the server and manage the limit of the Thunderbird mailbox by selecting the number of days as per your suitability. Next, choose the option Until I delete them.
  • At last, click on OK to save the changes.
  • Finally, your email will remain on the server till the specified day.

Contact the Email Service Provider

The email service provider can increase your mailbox size; you can contact them for the same and ask them to remove some emails from the server.

Wrapping Up

This blog has shown all the possible methods to resolve the Thunderbird error ‘Can’t receive emails when the Inbox is full.’ You can follow these methods easily as it does not require any technical knowledge. While performing the deletion process, it might be possible that you have deleted some important emails. You need not worry about this as you can regain your emails by using an innovative tool named Kernel for MBOX to PST. You can convert the MBOX file into various formats such as PST, MSG, RTF, HTML, and many more. This tool allows user to save their email in Gmail, Google Apps, Yahoo, etc. Also, it provides advanced filters to migrate the MBOX mailbox items such as date range, item type, etc. In addition, it provides a user-friendly interface that offers various facilities such as MBOX file preview, splitting option, multiple MBOX email clients, and many more.

Kernel for MBOX to PST