So you’re getting a bunch of junk mail and you want it just go away, but it keeps coming. Wouldn’t it be nice if Thunderbird could learn what is and isn’t junk and then make the bad stuff go away? Actually, it can. Let me show you how to set it up.
Go to Tools > Junk Mail Controls. Here you are going to find the preferences and settings for the built-in Junk Mail filter for Thunderbird.
To set it up, start by click the “Move incoming messags determined to be junk mail to:” box. Make sure the “Automatically delete junk messages older than _ days from this folder” option is also checked.
Next, check the box that says “When I manually mark messages as Junk:” and sure the “Move them to the ‘Junk’ Folder” option is the one that is selected.
Then, check the box that says “When displaying HTML messages marked as junk, santize the HTML”.
There is an option that you don’t have to check, but it might be a good idea to set up. At the top of the Settings tab, you can tell Thunderbird to not mark messages as junk if the message is sent from certain people. In my case, since I work at school I told Thunderbird to not mark any messages from people in my school address book as junk mail. You might want to do the same for your family address or just everyone in your Personal Address Book. This will help prevent good mail from going into the junk filter and being deleted.
Now that you’ve done all that, your junk mail controls are set up and ready to use. You’re probably saying to yourself, “What did I just do and why? How do I use the Junk Mail Filters?”
First, I’ll explain what each option just did and some of the other things you can do with it, but the “How do I use the Junk Mail Filters?” will be on another posting.
That first option you checked (Move incoming messags determined to be junk mail to:)just lets you determine what happens to messages that are considered Junk. We kept the default setting, which is for Thunderbird to create a folder labeled “Junk” and to move the messages there. You can create a folder of your choosing and move them there instead, but since we’re talking about Junk mail, it’s easier and sensible to just leave this setting on the default.
Also, under that same option, you can tell Thunderbird to delete messages in that Junk folder after a certain period of time. This will prevent you from getting spammed like crazy and having a huge inbox full of junk. The default setting I believe is 10 days, although I prefer to do it every two because I get lots of junk mail. If you wish to save all your junk mail, just leave this unchecked.
The second option (When I manually mark messages as Junk:) is similiar to the first option, but tells Thunderbird what to do when you manually mark a message as junk. You can either have them moved to the Junk folder or deleted. This will be important for when you first turn on the Junk Mail Filters because Thunderbird has to “learn” what you consider junk mail and then start applying that learning to new messages coming in. Eventually, Thunderbird will figure out what is junk and what is not and move them automatically to the Junk folder, thus using that first option. But for now, you’ll have to manually mark junk mail and teach the filter what is what.
The third option (When displaying HTML messages marked as junk, santize the HTML) is to prevent things from popping up that you really don’t want to see anyway. For instance, most junk mail that comes from “Adult” websites will probably include some pictures that advertise what they sell, which for most people, is not something they want to see. Instead of the spammer sending a huge picture file in every email (which would get filtered out by most email servers because of the size of the file), they tell the email to point to the picture on the spammer’s server. They do this using the website language HTML, which is what almost every page on the internet uses (in other words, HTML is not a bad thing). With this option checked, any HTML will not come up looking like a website, but will be checked out by Thunderbird first to see what is supposed to be there and will ask you what you want to see and allow you to mark a message as junk without having to view the pictures.