What happens to local mail is entirely dependent on the account type. Adding a new IMAP account using the office servers will simply add another entry to the folder list for a new account. (you can not change POP to IMAP. A new account setup is the only option. As these sort of switch overs are rarely happening in a controlled manner because DNS replication over the whole internet can take days you really want to have both in Thunderbird until you get account failure errors from godaddy. That way you will get the very last email on the old setup.

So right click your existing pop account in the folder pane and in the Account name change your existing account name to something else, perhaps add godaddy on the front or something. Thunderbird does not do well with duplicate account names, even though it is happy with the same address being configured twice.

Once you have renamed your existing account add the new account, specifying the office server information manually. It is very unlikely to autodetect in this situation.

When you old account start offering connection errors, copy all the mail in the existing account folders to the "local folders" location (ctrl+A will select everything in a folder), or you can use drag and drop. Just be very careful where you drop stuff. Once you are satisfied you have your copies, you can use the account settings page to access the account actions button and delete it.

Hi! I appreciate your help. Do you mean this sentence to drag from the old email to the new email? copy all the mail in the existing account folders to the "local folders" location (ctrl+A will select everything in a folder), or you can use drag and drop.

There are emails in different folders, so can I copy and paste those into the new address by creating folders of the same name on the new folder? It would get confusing if all the folders were in the local folders.

Thank you! ToSt

I see now what you mean by "local" folders - those are a completely different email address, my personal emails. I have 3 accounts (not counting the new one). I want to be able to copy the emails now in my old top account to the new top account we are setting up. The top one is my volunteer work emails.

I make folders on the new account we are setting up imap to match the old account pop. Then use ctrl + A to copy the emails from the old account and Ctrl + V to paste them into the new same-named folder I've created on the new account?? By account, I mean my email address. Will that work?

P.S. It wouldn't be Ctrl + V to paste. Instead, I would right click after selecting all the emails and select Copy To from the menu. Then select the new server and folder where I want to put them. Thank you again for all your help!

It would work, But I do suggest you start with a copy to local folders. Copies to IMAP folders are at best unreliable for large batches and the risks duplicate if you start copying from IMAP to another IMAP. Copies to local folders provides a backup if this goea wrong and allow you to verify successful copy.

Under no circumstances use move... that gives you no fallback it the process dies mid way. as you souce is already deleted.

Would this all be safer if I used a POP connection instead of IMAP? I don't have Windows 365. I have Windows 10, so I don't believe there is any benefit to using the IMAP for a connection, do you?

I apologize for this late reply. My pc start menu stopped working and I had to buy a new PC. Then I had to wait a week for the tech to come to fix it. I am just now back up and trying to configure programs he installed. Quite a lot of things to do :(

I appreciate your help!!

P.S. I can keep the data in the account I've named oldemailaddress. I would not delete it until a few weeks when everything is running okay in the newemailaddress account. Wouldn't it be my backup? I don't understand. Thank you again!