Configuring Opera's M2 mail client to work with POPFile

This text assumes that you have already set up M2 for your mail account and everything is running fine.

Setting up M2 to use POPFile as a POP3 proxy

Install POPFile.
In Opera, choose File → Preferences → E-mail.
Click “Manage accounts”.
Select the account you want to set up to work with POPFile and click “Edit…”.
Choose the “Servers” tab.
Note the name of the incoming server that you currently use.
Change the incoming server to 127.0.0.1
Edit the username box to contain the information “mailserver:username”. I.e. change the contents of this box thus that it now contains the name of the incoming server you noted in step #6, followed by a colon, and then the username that previously occupied the whole box.
Click “OK”.
That's it. If you have more accounts and you'd like to use them with POPFile, start over at step #2.

Go to the POPFile control center in your web browser (http://127.0.0.1:8080).
Switch to the “Buckets” tab.
Make sure that “Subject line modification” is switched to “Off”.
Make sure that “X-Text-Classification Header” is switched to “On”.
Right-click the spam folder in M2 and select “Properties…” from the context menu.
Switch to the “Filter” tab in the properties dialog.
Click “Add filter”.
From the drop-down box that currently contains the word “Subject”, select “Any header”.
From the drop-down box next to it that currently contains the word “Contains”, select “Matches regexp”.
In the edit box to the right of these two drop-downs, type “X-Text-Classification: spam”. If the bucket that you set up in POPFile as your spam bucket has a different name, e.g. “junk”, then enter that name instead of “spam”.
Click “OK”.
If you have set up more than two buckets in POPFile then create a new View or select an existing View in M2 and edit it's properties.
Again, change to the filters tab and let it filter any header on a regular expression. This time enter “X-Text-Classification: bucket-name” where “bucket-name” is the name of any other bucket you have set up in POPFile.

Important:

Make sure that each of your filters has a space behind the colon after “X-Text-Classification”.
Make sure that the spelling of your bucket names are the same in POPFile and M2.
There is no need to create a filter for your “Inbox” or “ham” bucket.