The Search for messages in drop-down list lets you select where you want to search. You can select any folder in any account, and then use the Search subfolders checkbox to indicate whether you want to search only the folder you selected, or that folder plus all subfolders off that folder.

You cannot specify more than one group of folders with this search, but later, when we talk about Search Folders we'll have more choices.

The radio buttons - Match all and Match any - only apply if you set more than one condition for this search. In this example, we want messages that meet both criteria, so we've selected Match all.

The first drop-down list indicates where we want Thunderbird to look. In this case, we want it to look at the Subject line. You can search various headers (To, From, Subject, CC), the body of the message, or its age or size.

The second drop-down list lets us choose the matching condition (the choices here depend on what we chose to search). In this case we can either select contains or begins with.

Next we enter the text we want Thunderbird to look for.

Since this search involves two criteria, clicking on the plus-sign button creates a second row, which we've filled out to look for messages older than 120 days.

Click Search to start the search process. Depending on how many folders you've asked Thunderbird to search and how many messages you have stored, it may take a few seconds or a few minutes. The search results show in the bottom half of the window.

Once you've performed a search, highlight a message, then

• Click Open to read that message
• Click File then select a target folder to move the message to that location
• Click Delete to delete that message
• Click Open Message Folder to open the folder where the message you selected lives
• Click Save as Search Folder to create a special kind of folder, one which remembers your criteria and updates itself We explain more about Search Folders next.

Give your folder a descriptive Name, so that it will be easily identifiable.

Use the Create as a subfolder of drop-down list to choose where the folder will appear in your folder hierarchy.

Click Choose (next to Select the folders to search). You'll be shown a complete list of all folders and all subfolders across all accounts. The folders you searched earlier will be selected, that is, they have checkmarks. Use this list to expand or limit the folders you want searched. Any combination is allowed. (There's no automatic searching of subfolders here - if you want a subfolder searched, make sure you give it a checkmark.)

If you use IMAP to store messages on the server, put a check in the Search Online checkbox. If all your mail is stored on your own computer, clear this checkbox.

The search criteria you used earlier will be shown here. You can modify it in any way, if you so desire.

When you click OK your search folder will be created where you specified. The icon for a search folder includes a magnifying glass, so you can tell it isn't a normal folder.