Your profile folder is in there, so yes, you definitely want to keep that folder:

Profiles - Where Thunderbird stores your messages and other user data

Thank you. Would you mind explaining why exactly I need it. Is it for Thunderbird to function properly? Since what I want to keep is already stored online in my email accounts why do I need to also keep it on my computer taking up so much space? Can it be moved to an external hard drive? I am sorry if I am asking stupid questions but my computer's hard drive is not large and I do not want to accumulate so much stuff on it.

Hi suslikonline, there are two ways to configure mail in Thunderbird, and both of them save mail locally:

• IMAP - Thunderbird creates a local replica of your server mailbox
• POP - Thunderbird downloads a copy of new messages in your Inbox, and potentially deletes them from your Inbox

If you do not want a local copy, why use a stand-alone mail program, why not work with your mail in a browser using your mail provider's website?

Regarding moving your mailboxes off your main hard drive, there might be an article on that. I don't have any personal knowledge of whether that is possible.

I am using Thunderbird because I have three different accounts and want to be able to check them at the same time. Thank you for the explanations!