Thunderbird Quarantine Inbox Issue – Resolve the Problem

admin | November 4th, 2017 | Mozilla Thunderbird

There are powerful antivirus scanners available in the market like Norton and Symantec. These identify an infected message as soon as it is received and send it to quarantine. This contains the infection from spreading and later the file can be deleted or repaired based on user’s choice. This causes problems with the Thunderbird email client using the file to store mailbox data. Repairing or deleting the file further incriminates the issue. Thunderbird quarantine Inbox issue can prove to be very difficult to manage mailbox securely using an antivirus scanner. It can cause a lot of raucous in a business environment that deals with constant communication. This post talks about the Thunderbird quarantine issue and suggests some solutions to fix it. Read more about it in the following section.

Quick Glance on Thunderbird Quarantine Inbox Issue

Thunderbird is an email client that that is used to share sensitive information and emails. It not only provides email features but also organizes contacts, notes, calendar, tasks etc.
All messages of Mozilla Thunderbird are stored in inbox folder in the profile folder. However, each folder is stored after the name of the folder. Certain, antivirus considers that each message is stored separately, on the detection of virus in an inbox, the entire file is subjected to deletion, rather than deleting that particular message. Thunderbird Quarantine Inbox Issue arises because of the design flaw in some antiviruses. The issue is not with Thunderbird but with the antivirus.

Set Antivirus Utility to Remove Quarantine Mailbox

Set an antivirus on asking before automatic deletion or restore the quarantined files.

Make settings so that anti-virus should ask permissions before doing automatic deletions or restoration of quarantined files.

Turn off Email scanning Options because it corrupts email files more than virus do. Moreover, it slows down the speed of PC. If the users want to scan then scan only incoming messages because some antivirus program has issues with outgoing messages.

No dependency on Email Service Provider. Users should not rely on email service provider for the execution of scanning. There will be much more security when emails are scanned by the particular domain.

Manual Methods to Fix Thunderbird Quarantine Inbox Issue

Following are the steps that need to be followed to fix Thunderbird after an MSF file is stuck in quarantine:

Solution#1 Prevention From Loss of Emails as Inbox Gets Quarantined

Keep complete mailbox empty by saving old messages into a separate folder. For this way, some emails may get affected even when the antivirus has deleted an inbox. Set the Mozilla Thunderbird to leave email messages on a server instead of removing them instantly. According to this, users can easily download their emails even when antivirus damaged inbox file.To leave the copy of messages on the server for some days, follow these below steps:

  • First, open Thunderbird to prevent future communications from infection
  • Then, go to Tools>>Account Settings>>Server Settings
  • Now, mark the option ‘Leave messages on server’ and specify the number of days Thunderbird Antivirus issue
  • Next, go to Edit>>Preferences>>Mail>>Newsgroup Settings
  • Then, choose Server Settings and select ‘Leave messages on the server’ option
  • Again, set a number of days to avoid complete mailbox from corrupting in case of infection
  • Now, these messages can be downloaded again from the server. They are safe there in case of hard disk/drive failure from corruption.

Solution#2 Fix Thunderbird Quarantine Inbox Issue

  • In antivirus program, exit the “auto-protect” option or disable the antivirus software
  • Now, next step is to take a backup copy of the profile folder
  • Then, make a copy of inbox folder or previous inbox with quarantine but Thunderbird seems to be overwritten
  • After this, right-click on the specific folder to create a new folder i.e., OldInbox and copy everything in it
  • Next, take inbox or other affected email messages out of quarantine
  • Delete the unpleasant messages from Thunderbird application
  • Remove the trash folder for an affected account
  • After this, compact the desired folders from affected accounts
  • Lastly, re-activate the antivirus or malware software
  • Finally, you have to confirm that all emails are available or not

Solution#3 General Approach to Fix the Issue

  • Open the antivirus application and view quarantine and display name of that file
  • If it describes anything else except the Inbox then, just delete it
  • If the user does not read the file name as inbox then, click on the Restore option and follow the above process to fix this issue
  • Alternatively, drag all email messages to a new specific folder then, clean the inbox in Norton application, which contains rest of emails to solve Thunderbird Quarantine Inbox Issue
  • Users can set up the Norton application to exclude the folder from the scan. Due to this reason, the entire inbox cannot be quarantined. Only virus-infected email to be quarantined


Antivirus software is quite important to securing communication over the internet. It is essential to know the steps to fix Thunderbird quarantine inbox issue affecting mailbox data integrity. This post mentions all the precautionary steps and individual solutions to make sure this issue is not repeated on any computer.