How to Import POP Messages from Thunderbird and Retain Folder Structure

Thunderbird stores each folder of messages in an mbox file. These are located in Thunderbird's profile folder under a folder for the account.

For example, on WinXP in "C:\Documents and Settings\user\Application Data\Thunderbird\Profiles\profile_name\mail\pop.example.com", you'll see "Inbox", "Sent", "Trash", "Junk", "My Folder 1", and "My Folder 2" for example. All of these files don't have an extension. Ignore the .msf and .dat files as those don't contain messages. ("C\users\user\AppData\roaming\Thunderbird"... for Vista/Win7)

By importing each Thunderbird mbox file into Opera separately (into the same account), you can retain your sorting of messages into folders.

Here's how you do it, in the following order (but read all steps first):

Make Sure All Messages for the Account Are Fully Downloaded in Thunderbird

In Thunderbird, if you use any settings that tell Thunderbird not to download all parts of a POP message, make sure those settings are turned off and you check for new messages so that each message in Thunderbird's store is complete.

For example, in Thunderbird, if you goto "Tools -> options -> the account -> disk space", there's a "do not download messages larger than" option that should not be checked. There's also a "fetch only headers" option under "server settings" that should not be checked. Make sure "Automatically download new messages" is checked.

Note: It's best if all messages are removed from the server and only stored locally in Thunderbird on your computer. If any messages are left on the server, you'll have extra work to do after you're done importing. See the duplicate removal section later on for more info.

If you want to remove all messages from the server and only keep them in Thunderbird, goto "Tools -> options -> the account -> server settings" and uncheck "leave messages on server". But, understand that this will remove all the messages from the server so that they won't be accessible from other computers.

Compact Folders in Thunderbird

In Thunderbird, compact all folders for the account and shut down Thunderbird. You must do this to clear all the deleted messages that are hidden in Thunderbird's mbox files. Otherwise, Opera will import them as messages.

You can do this by right-clicking on each folder and choosing "compact". Or, you can do this by going to File and choosing "Compact folders". It's best to do both ways for good measure.

Setup the POP Account in Opera

In Opera, goto "Menu -> Mail and chat accounts -> add" and follow the wizard to set up Opera to connect to your POP account.

But, DO NOT enter your password anywhere. Finish the wizard without entering it. And, if an error console pops up, just leave the console up till you're done. This is so Opera doesn't fetch any messages from the server yet. Or, instead of leaving the error console up, go into the account's properties "Menu -> Mail and chat accounts -> the account -> edit -> incoming tab" and turn off checking of new messages. Then, close the error console. You can then change the settings back when you're all done.

Once the account is set up, right-click in the mail panel (on a view or a blank spot) and set "show messages from" to just the account you just created so that you're working with messages just for the account. This is very important for the import directions below so you don't accidentally delete messages from other accounts. Also note that if you restart Opera, "Show messages from" reverts to "all". So, if you restart, make sure you set "show messages from" to this account again before continuing. Again, be very mindful about the messages you're working with.

Import Trash

In Opera, goto "Menu -> Settings -> Import and Export -> Import Mail -> Import Generic Mbox file -> add".

Browse to Thunderbird's "Trash" mbox file for the account and choose "open".

Make sure "import into" is set to the existing account you created and choose to import.

Click finish and close out of the import wizard completely.

In "All Messages/Received", select all messages and press del to move them to "All Messages/Trash".

Import Spam

Right-click "All Messages/Spam" in the mail panel, goto properties and uncheck "Learn from labeled messages". If you want Opera's spam filter to learn where you have to train it and remove a bunch of false positives for a while, you can turn this back on after you're all done importing. Just don't leave it enabled now.

In Opera, goto "Menu -> Settings -> Import and Export -> Import Mail -> Import Generic Mbox file -> add".

Browse to Thunderbird's "Junk" mbox file for the account and choose "open".

Set "import into" to the existing account you already created and choose import.

Click finish and close out of the import wizard completely.

Once the messages are imported, in "All Messages/Received" select all of them (the trash messages will be hidden) and mark them as spam by clicking the Spam button on the mail toolbar above the message list.

Then, in "All Messages/Received" and "All Messages/Unread", click the view button on the mail toolbar above the message list, goto "show" and uncheck "show spam". This will hide spam from those views.

Import Custom Folders

Ctrl+left-click in the "Labels" access point to deselect all labels. Right-click on the "Labels" access point header and choose "new label". Name the label after the email address for the account, you@example.com for example.

For each custom folder you created in Thunderbird:

Select the you@example.com label you created above. Right-click and choose "New Label" so that it becomes a sub-label under you@example.com.

Rename the label to have the name of the folder you're going to import. The label's name should be in edit mode. But, if it's not, right-click it, goto properties and rename it there.

Right-click on the label, goto properties and set "Hide these messages from other views". This will make the label act like a folder. Also, make sure "learn from labeled messages" is not set for the label. Don't worry about other settings for the label.

In Opera, goto "Menu -> Settings -> Import and Export -> Import Mail -> Import Generic Mbox file -> add".

Browse to Thunderbird's mbox file for the folder for the account and choose "open".

Set "import into" to the existing account you already created and choose import.

Click finish and close out of the import wizard completely.

Once the messages are imported, in "All Messages/Received", select all messages (all other messages that you've previously imported will be hidden) and drag them to the label you created. Alternatively, you can use the label drop-down in the message list to apply the label to the messages. They should then disappear from "All Messages/Received" and will only be shown in the label's message list.

Repeat for each folder.

Import Sent

In Opera, goto "Menu -> Settings -> Import and Export -> Import Mail -> Import Generic Mbox file -> add".

Browse to Thunderbird's "Sent" mbox file for the account and choose "open".

Set "import into" to the existing account you already created, set "move to sent" to "Sent" and choose import.

Click finish and close out of the import wizard completely.

Then the sent messages will now be shown in "All Messages/Sent". And, they'll shown in the "Sent" view under the POP access point for the account (if you're using Opera 11.10+).

However, by default, Opera shows sent messages with your other messages too. If you don't like this, in each message list you want to adjust, click the view button on the mail toolbar above the message list, goto "show" and uncheck "Show sent".

Import Inbox

In Opera, goto "Menu -> Settings -> Import and Export -> Import Mail -> Import Generic Mbox file -> add".

Browse to Thunderbird's "Inbox" mbox file for the account and choose "open".

Set "import into" to the existing account you already created and choose import.

Click finish and close out of the import wizard completely.

That will import your "Inbox" messages, which will show in "All Messages/Received". And, they'll show in the "Inbox" view under the POP access point for the account (if you're using Opera 11.10+)

Set Username and Password

Now that you're done importing, goto "Menu -> Mail and chat accounts -> the account -> Edit -> Servers tab" and set your password for the incoming and outgoing servers.

Then, hit the Check/Send button on the mail panel toolbar so that Opera fetches any messages that are on the server for this account.

Do not mark any messages as read yet.

Remove Imported Messages that are Duplicates of Ones on the Server

If any of the messages in "All Messages/Unread" are duplicates of messages anywhere else, you need to delete the read copies that are not in "All Messages/Unread" as they're not tied to the copy on the server like the newly-fetched ones in "All Messages/Unread" are.

For example, if you have the message "Test Mail" that was imported into Opera and is now in the "Family" label and Opera fetched the same message from the server, you need to go into the "Family" label and permanently delete that copy. Then, you need to drag the "Test Mail" message that's in "All Messages/Unread" into the Family label and mark it as read so that the good copy of the message is now in the "Family" label instead of the invalid copy.

The easiest way to do this is to look at the "All Messages/Received" message list with "View button on mail toolbar above message list -> show -> show hidden, show trash and show spam" set and sort the list by subject. That will group messages with the same subject together. For any duplicates, you should see both the unread copy and the read copy. The label column for the read copy will show what label it's in. Then, you just take note of what label the read copy is in (if any), delete the read copy, apply the label (if it should be in a label) to the unread copy and mark it as read.

Once you're done getting rid of duplicates, you can uncheck "Show hidden", "Show Trash" and "Show Spam" for "All Messages/Received" and you can changes the sorting back to default or how you like.

Note: The more messages that are left on the server, the more duplicates you're going to get. If all messages that are in Thunderbird are left on the server, there's no sense in trying to import from Thunderbird. Instead, just set up the POP account in Opera and let Opera fetch all the messages. Then, create Labels (with "hide these messages from other views" set) for the corresponding custom folders you created in Thunderbird and drag the messages you want into each label.

Notes

That's it. You're done for that POP account. Repeat all these steps for any other POP accounts you want to import from Thunderbird.

Note: Some Thunderbird users that used Thunderbird 2 and used a global inbox and have been upgrading ever since, might have all their messages for an account (or all accounts) in the mbox files under "mail\Local Folders" instead. Importing from "Local Folders" instead should work just fine *if* they only contain messages from one account. If they contain messages from all accounts, you might make a mess if you import those. In this case, see <http://kb.mozillazine.org/Global_Inbox? for how to convert a global inbox into separate account folders before trying to import into Opera.

Is there a way to import all custom folders and structure into labels rather than one at a time?

I have 100s of folders and subfolders and don't want to have to go through and do each individually.

Cheers

Originally posted by originalashlin:

Is there a way to import all custom folders and structure into labels rather than one at a time?

If the "Menu -> settings -> import and export -> import mail -> import from Thunderbird" (it doesn't work as expected so I haven't messed with it in a long time) option doesn't do it, then no.