In your profile. Specifically, in mailbox or mboxrd format files, which have names like Inbox or Sent with no extensions. Note that the accompanying *.msf files are just indexes and don't need to be backed up. Messages are stored as received, verbatim, with attachments inline.

https://support.mozilla.org/en-US/kb/profiles-tb https://en.wikipedia.org/?title=Mbox

The reply is too technical for me. I'm about to install Windows 10 for the 3rd time (the first 2 crashed and caused chaos). I want to make a backup of all my files first. I keep all my data on a 'D' (data) drive which makes backing up quick and easy and with a folder for the data of each program, finding anything is also easy. I want to store all my emails (sent and received) on the D disk in an email folder. Can this be done, and how.

You can certainly put your profile in any folder that you want. You'll have to edit profiles.ini to tell Thunderbird where it has been put, or use the profile manager to configure Thunderbird to find the profile in its new location.

One of the links told you where to look:

https://support.mozilla.org/en-US/kb/profiles-tb#w_where-is-my-profile-stored - this page will detect your OS and adjust itself accordingly.

Another way to get there is to go to Help|Troubleshooting Information and click the "Show Folder" button.

The profile location is hidden by default. You'll need to enable viewing of hidden files.

Thanks for your help but I got lost. For instance I couldn't find 'profiles.ini', I didn't know how to find Hidden Files (but I got there in the end), in the link was this sentence - The Windows Explorer window will show the name of the profile as well as the path to it. I got the path, but what was the profile name? At that point I gave up. Why not a simple question under 'Tools', 'Accounts settings' in which the user could select the required location. Thunderbird is a good product, but as more and more people use it, there will be proportionally less users who understand the technicalities of it and the unusual procedures will have to be explained in a more simple language. Anyway, thanks for your help.

I'm having the same issue. I know where my profile folder is, I can see 'hidden' files in explorer, but I have no clue where the attachments reside. I've read this page three times and followed the links but cannot locate the attachments in my TB folder.

I received a suspicious email and attachment and want to examine it before clicking on it, but I can't find the attachment file.

thanks,

There is no attachment file. The mbox format stores the whole message, as it arrived, verbatim. Since attachments are encoded and included inline, you'll find them within the message in the mbox file.

Of course they may be encoded and non-trivial to read.

So, to extract or work with an attachment, find the email that came with it? That is very different than Eudora. Is there an advantage to handling attachments the way TB does?

You look at the email message in the inbox, you save its attachment. No need to go rummaging about in the mail stores.