How to Resolve Error: “No Valid MBOX files were found”

  author
Written By Andrew Jackson
Anuraag Singh
Approved By Anuraag Singh
Published On July 12th, 2022
Reading Time 6 Minutes Reading

No Valid MBOX files were found Error

Nowadays, the most commonly used means of communication is through emails that can only be achieved by using any of the available email applications. As you can see, the demand of professional email clients is increasing day by day that’s why software market is full of different email clients and a user can select any of them depending upon their demands and needs. Depending upon the emails clients, emails are stored in one or other kind of file format that may or may not be compatible with other email clients. Now, the different operating system supports different email clients and different file format. One such file format that is used by many operating systems is MBOX file format. Moreover, it is the most widely used file format to save the electronic mail messages. MBOX file format is used by various available email clients like Entourage, SeaMonkey, Pocomail, Mulberry, Apple Mail, Opera Mail, Netscape Mail, Spice bird, etc. But there are some situations that lead to corruption in MBOX file. Whenever a user encounters a MBOX file corruption situation, an error message is generated. Therefore, in this blog, what are the root causes of such type of error and how to resolve no valid MBOX files were found the error is discussed.

Causes of ‘No Valid MBOX file were found’ Error

Most of the time users face some error messages such as Apple Mail no valid MBOX file were found whenever they tries to import MBOX files. Now, to properly understand the situation, here in this segment, we have discussed the root causes of this error.

  • Whenever a user try to access an inappropriate directory, this type of error messages encountered.
    The user is importing MBOX file from one version of Mac OS to another version then, due to compatibility issue users face such type of errors.
  • Another possible reason is that corruption in the MBOX file that a user wants to import.
  • It may also be a case that a user try to import MBOX file to external device such as hard disk.

How to Resolve No valid MBOX files were found error

Situation 1: When a user archived the old mailbox as MBOX file and try to import that MBOX file to an external device. The user clicks on Import option in the file menu and tries to import one file at a time into mail, but unexpectedly every time a dialog box encountered, which say “no valid MBOX files found”. Now, the question arises How to import MBOX file into the mail?”

Solution: Now, the method that a user needs to follow steps to import MBOX file is explained in next situation.

Situation 2: When a user tries to import MBOX file from one version of Mac OS 10.6 to Mac OS 10.7, there are some compatibility issues that generates errors message that no valid MBOX files were found. Here is described the migration from Mac OS 10.6 Snow Leopard to 10.7 Lion. These steps can be helpful for an older version of the operating system.

Solution: First of all, before starting the migration process, a user needs to take backup of the following:
~/Library/Mail/
and
~/Library/Preferences/com.apple.mail.plist

Note: If a user wants to open hidden user’s library folders in the Finder then:

Copy ~/Library/ and select Go >> Go to Folder and paste the path>> Go

Now, to migrate to the different version of Mail.app that uses slightly different file formats or database structure, importing process is done.

Note: For importing process, it is necessary to have access to the old messages originally located in this folder:
~/Library/Mail/

In order to import to the different version of Mail.app follow the steps mentioned below:

1. Transfer the Mail Rules
When is not open, a user needs to copy MessageRules.plist from the old Mail folder to the new one ~/Library/Mail/V2/MailData/. If MessageRules.plist.backup is there, delete it.

2. Now, in the Mail.app and in the Preferences confirm the presence of the rules

3. Import MBOX file to Mac Mail
a)  Select File >> Import Mailboxes and then, choose Apple Mail >> Continue

If a user tries to select Files in mbox format to import mailboxes individually then, it has returned an error “No valid MBOX files were found”. Therefore tries to import mailboxes instead of separate MBOX files.

b) After that click on Choose button to select the Mail folder from where a user want to import from. At this step, a user can preview all content that found in mailboxes

Here, if a user wants that he can import selective items also by checking or unchecking the respective boxes.

c) Now, click on Continue button to begin the importing process.

d) Verify and bring Everything in order
1. Close and open Mail.app again

2. Now, check the Import Mailbox and move the imported mailboxes to correct location

3. After that, check whether search tool works well or not. If the search tool does not work properly then recreate SpotLight index with the help of shell command:
sudo mdutil -E /

4. Verify that the mail rules are present in the Preferences or not.

Situation 3: When a user is importing MBOX file from incorrect directory level there is an error message displayed on the screen that no valid MBOX files were found. Therefore, to overcome such type of situation, a user needs to shift the directory level by one.

Solution: To resolve the error stated above follow the steps mentioned below:
1. First of all, backup directory level by one

2. Now, select the Mailboxes folder from location:
/Home/Library/Mail/Mailboxes/

3. After that, a list of MBOX file is displayed

4. Select the MBOX file that a user want to import and start the import process.

Conclusion

As most of the users are querying about the how to resolve no valid MBOX files were found so, in this blog, different manual approaches based on different situations are discussed. However, manual procedures are very time-consuming. Therefore, to ease the process, one can use a third party tool that is Mac MBOX Converter. It helps in resolving all the issues related to MBOX file. A user can perform both selective and multiple migrations of files. Moreover, the tool also provides the trial version that can be used for free before purchasing it.

  author

By Andrew Jackson

I am SQL DBA and SQL Server blogger too. I like to share about SQL Server and the problems related to it as well as their solution and also I do handle database related user queries, server or database maintenance, database management, etc. I love to share my knowledge with SQL Geeks.