My assumption is that this is a Thunderbird related question, not Firefox. I'll see if maybe an administrator can move it to the right spot for you. You might get more answers that way. However, I can tell you that most email providers will not accept a 32MB attachment. Most will limit you to 25MB, but others like Outlook will limit you even lower. It's important to remember that this a cumulative total including the text of your email. So the file would need to be even lower than the maximum. If you are having trouble attaching a file to your email because it's too large, using send.firefox.com is always a good option. Hope this helps.