Lets consider some things here.

1. You computer died. I have no idea why, but it is faily common for the hard disk to crash, so there is no guarantee informarion that used to be there is there anymore for you to copy.

2. You obviously copied your data somehow or some of it from the old disk. Did you right click and select properties to confirm that the copy and the original had the same space and file numbers? Perhaps your copy did not copy everything.

3. When you copied from your intermediate device (USB drive or whatever) did you again check that the copy on the new hard disk actually matched the copy?

I find lots of folk with issues simply did not copy everything. I don't know what they do, but quite probably pull out the USB drive as soon as the dialog tht says copying is gone, despite windows still copying to a USB sometime minutes after the dialog goes away.

4. IS your mail in the profile folder or did you change the directory in account setting to somewhere of your choosing. There were a lot of folks that moved it to my documents at one time and then left their data on the old XP machine. Or copied it to later windows versions with out updating the location which is now users.

If you have critical data on a computer it has been best practice to make backups for the last 50 years. Few people do it and then they look for someone to undo the failure. It is a large part of the popularity of cloud storage. When it fails there will be lots of disappointed folks, because all those end user agreement do not guarantee your data, only best endeavors.

Perhaps you might consider long term investing some time in backups. I use windows backup to create a backup once a week, so I will not be more than a week behind in the event of a computer failure. (something that is really inevitable on older drives) and when it occurs catastrophic to the device in question.

My Computer motherboard died. I have the hard drive in an enclosure. I am working with MacOS. I got some help with moving my profile yesterday, and it moved my emails, but I am still missing my collected addresses and saved addresses. I didn't move the whole profile folder, just the ****.default folder. I had already set up my email accounts on the new computer before I realised that I was only getting emails going forward and had lost the old ones, and the addresses. So when I replaced the ****.default folder, it brought in my old settings and the old emails. Doubling up my accounts on the new computer. Now what is happening is the new emails are coming into the new accounts that I set up, and the old account is there too with the old emails. Do I need to start again? Should I have replaced the whole Profile folder? Will that resolve the address issue? How do I merge the emails so they are all in one place? I have learned the hard way to make backups regularly. Don't worry, I have stuff well backed up. Thank you for your advice.