Keeping an Eye on Folder Sizes in Thunderbird

It can be handy to be able to look at your email folders and quickly see which ones are using up a lot of your email quota. If you use Thunderbird to access your email it’s really easy to add folder sizes to your folder pane:

  1. In Thunderbird, check the option View->Layout->Folder Pane Columns. If you don’t have the menu interface on top, instead use the menu stack icon (three stacked lines) over on the right to check Preferences/Layout/Folder Pane Columns.
  2. There are options to show the total number of messages, the number of unread messages, and the size of the folder. To access them, click on the tiny icon at the top of the folder pane, to the right of the “Name” column and any others that might be showing—it looks like a little table with a downward pointing triangle. Set it so that only the size of the folder is checked.

The sizes that you’ll see are marked as being in KB, MB, or GB, so it’s helpful to understand what those mean:

  • A “byte” is the amount of space used to store a single character.
  • “KB” stands for “kilobytes,” which means approximately 1,000 characters.
  • “MB” stands for “megabytes,” which means 1,000 Kilobytes, or approximately 1,000,000 characters.
  • “GB” stands for “gigabytes,” and means 1,000 megabytes, or approximately a billion characters.

The default quota size for Hampshire email accounts is 2.5 GB, which would be 2,500 MB or 2,5000,000 KB. Keeping this in mind, when you scan folder sizes trying to bring down your quota you can skip over folders expressed in KB and focus on those measured in MB and GB.