How to Fix Thunderbird Email Inbox Full Error? Quick Method

Thunderbird is a widely used open-source email platform, as it has 20 million active users. It allows for sending and receiving emails with POP3 and IMAP accounts, along with many more features. It offers features like fast message search, customization, add-ons, and themes, etc.

Why Does Thunderbird Inbox Get Full?

• Thunderbird stores its data in MBOX file but when it becomes larger then it will affect larger performance.
• POP3 downloads all emails on your local machine due to these inboxes getting filled quickly without syncing the server.
• Emails with large attachments take lots of storage and Thunderbird doesn’t automatically remove or detach them.
• Large MBOX files get corrupted quickly, preventing Thunderbird from receiving or displaying emails properly.
• IMAP synchronization errors can cause Thunderbird to store emails locally when they are deleted from the server.

How to Check Thunderbird Inbox Storage Usage?

If you are experiencing Thunderbird inbox full not receiving emails then it’s crucial to check Thunderbird storage. As Thunderbird doesn’t display storage but you can check it by following the instructions as we have explained below:

Method 1. Check Inbox Size using Thunderbird Folder

1. Open “Thunderbird” and right-click on the Inbox folder.
2. Click on “Properties” from the menu and press on the General Information tab.
3. “Check folder size”, which shows the storage used by inbox.

Method 2. Check Email Account for the Webmail Interface

1. Login to your email service provider and check the “Storage Quota”.
2. If your webmail storage is closest to full, then it may “Prevent Thunderbird” from receiving new emails.

Method 3. Check Thunderbird Usage for Local Folders

1. Go to Thunderbird profile folder: C:\Users\Admin\AppData\Roaming\Thunderbird\Profiles
2. Mac OS: ~/Library/Thunderbird/Profiles/YourProfile
3. Linux ~/.thunderbird/YourProfile

Method 4. Use Account Settings to check Storage Limit

1. Go to Tools and click on “Account Settings”.
2. Navigate to “Disk Storage” and check if any file size restrictions.

What to Do When Thunderbird Storage Gets Full?

• Delete unnecessary emails or larger attachments from Thunderbird.
• Empty Trash and spam folder to free up Thunderbird storage.
• Compact folders to permanently remove unwanted emails.
• Archive older emails into local folder.

Common Issues When Thunderbird Inbox is Full

• A full inbox can block to send or receive new emails or cause them to bounce back free up space, delete unnecessary emails and compact folders.
• Large inboxes can freeze Thunderbird, making search and loading slower.
• Overloaded Thunderbird inbox can cause missing emails or corrupted mailbox files to repair the inbox file and reduce storage usage to fix it.
• A fully sent folder may prevent sending emails, displaying storage limit error, clearing the sent folder and enabling auto-delete can solve these.
• Excessive storage can cause attachment issues especially in IMAP Account downloading attachments separately.

Method 1. Delete Unnecessary Emails

1. Open “Thunderbird” and navigate to the inbox.
2. Select “Outdated or unwanted emails”.
3. “Empty Spam, Junk and Trash folder” to free up storage.
4. Use “Thunderbird search filter” to find and delete large or older messages.

Method 2. Archive Emails to Free Up Storage

1. Open “Thunderbird inbuilt Archive feature” to transfer old emails to local folders.
2. Archiving reduces the “Mailbox Size” while keeping email accessible for future reference.
3. Navigate to “Message” and click on Archive to set up automatic archiving in Account Settings.

Method 3. Compact Folder to Reduce Mailbox Size

1. Thunderbird doesn’t claim storage automatically, you must “Compact” the folder automatically.
2. Click on file and press on “Compact folder” to reduce mailbox size.
3. Enable “Auto-compaction” in Settings and click on General option.
4. Now, press on “Disk Space” to prevent future inbox bloating.

Method 4. Export Attachment Separately

1. “Large Attachments” take significant storage in the inbox.
2. Open email with Attachments, right-click on the file and press “Save As”.
3. Store in “Local or Cloud storage”.
4. After removing the “Attachment option” to free up storage.

Method 5. Increase Mailbox Size Limit

1. Some “Email Providers” impose mailbox size restrictions.
2. Check your “Email Storage” allowing more storage.
3. “Adjust Thunderbird local storage” settings by clicking on Account Settings and press on “Synchronization and Storage” to manage mailbox size effectively.

Method 6. Backup and Delete Old Emails

1. Use “Thunderbird Import/Export NG Tools Add-ons” to export emails as MBOX, EML or PST files for backup.
2. Once backup, “delete Unwanted emails” from the inbox to free up storage.

Method 7. Repair and Optimise Thunderbird Files

1. “Corrupt and oversized MBOX files” can create storage issues.
2. Use the “Thunderbird Repair option” by choosing the inbox and right-clicking on it.
3. Select Properties and press “Repair Folder”.

Prevent Inbox from Getting Full Again

• Setup Auto-Delete Rules for spam and trash folder.
• Enable Email forwarding to another account for long-term preservation.
• Use Cloud Storage to store old emails periodically.

Steps to Fix Thunderbird Email Inbox Full Error

1. Download and install the “Thunderbird Backup Tool” on your system, then launch it.
2. Click on “Convert Emails” and select the configured Thunderbird mailbox data.
3. Select the “Thunderbird folders” you want to convert.
4. Choose the export option from the list of “Saving Options” and select advanced filters.
5. Browse the destination and press Next to fix “Thunderbird email inbox full error”.

Prime Characteristics of Automated Tool

• This software allows you to migrate Thunderbird emails to Outlook, Microsoft 365, Gmail, and all IMAP Supported email servers.
• It offers a simple initiative interface to easily use by any level of users.
• You can also convert Thunderbird emails to PDF, PST, MBOX, TXT, HTML and many more.
• With this tool you can also use the filter option to convert mailbox data as per date range, subject, sender blank address, receiver blank address, root folder and more.
• This tool allows you to extract phone numbers, email addresses and extract attachments from Thunderbird.

Common Queries about Thunderbird Email Inbox Full Error

Why does it say my Email Inbox is full?

Thunderbird say inbox full cannot receive email, it happens due to unnecessary emails, larger attachment or email provide storage get exceed. To solve this, wipe unwanted emails, remove attachments and compact folders to free Thunderbird storage.

How do I Empty my Inbox in Thunderbird?

To empty your Thunderbird mailbox, delete unnecessary emails and move important ones to local folders then empty the Trash folders. Finally, compact your inbox by going to file and click on Compact Folders to permanently free up storage. You can also set up Auto-archive for better email management.

How do I Clean up my Thunderbird Inbox on Exit?

To clean up Thunderbird inbox automatically on exit, enable Auto-compaction by going to Settings and click on General and disk space and select Compact all folders when it will save X MB. You can also create filters to move old emails to archives or delete them based on rules.

Overall Reflection

When Thunderbird says “Inbox Full” or you want to fix the Thunderbird Email Inbox Full error, it may indicate that the inbox is full or the profile has become corrupted. You can opt for a solution as discussed in this post, but before proceeding, take a backup of your mailbox data using an automated tool. This ensures that you can migrate the entire or specific Thunderbird mailbox data without losing any information.