Migrating from one IMAP account to another: can I just change server data?

Question

A customer of mine is switching ISPs, so I have to migrate his email from his old IMAP server account to the new one. (He isn't using Gmail; he's using Windows Live Mail). I was wondering which approach would be the best:

• Moving all his emails by dragging them from one account to the other in the mail client. I have heard people saying that you can do this with Thunderbird; can you do it in Windows Live Mail too?
• (This is the approach that I was thinking about). Just edit his current IMAP account info and replace the old server for the new one. What worries me about this approach is that he has a lot of emails in his current account; if I just change the new of the IMAP server, will his old emails vanish from his local computer?

I am asking specifically about the latter approach, in order to make sure I don't mess up and accidentally delete all my customer's email. Does anyone know this?

Answer 1

IMAP protocol keeps all of the emails on the server, so if you edit the server details, the emails will not be there - you are just pointing to the new "empty" server.

You need to copy the emails to the new server if you are using IMAP - Windows Live mail allows you to do that.

Answer 2

IMAP stores emails both locally and on the server, but those programs will keep the data linked to the server, so if you change the server address details, the mailclient will look up what data is on the server, sees that its empty, then deletes all locally stored emails too.

What you want to do is first create a 2nd IMAP account to the new environment, then drag and drop the mails from one server to the other. Once migrated, remove the old account.

Don't forget about contacts and stuff they may be using.

This is the only way.

Answer 3

If clients's current account times out you won't have access to the server stored folders content.
To have a client software independent backup and ease transfer I'd use a program like
IMAPSize or
MailStore.