Moving my mail settings and messages

I usually migrate, but the last time I did a Time Machine restore, my mail.app folders got corrupted. So before I begin, I need to know if you have all your email sitting on a server or is it only on your Mac? If you have email sitting on a server, it's very simple to set up the same accounts on a new machine and all the email just "shows up" on the new machine. But if the only copy you have is in mail.app, migrating to another machine is a bit more tedious.

For now, I'm going to assume you have your email on a server, ie gmail.

Step 1 is to run keychain access on your old machine to get the passwords of all your email accounts (if you don't know them). Write them down so you can enter them on your new machine.

Step 2 is to open mail.app on your new Mac and enter the accounts 1 by 1, using the passwords you looked up in step 1. Make sure you pick IMAP for your email so messages get copied to your Mac but not deleted from the server. POP3 is an old sloppy method of getting email and you should avoid using it even if it means finding a new email provider that supports IMAP.

That's it. Two steps. Done.

Now I'm going to assume you have your only copy of a lot of your email sitting in Mail.app on your old Mac. First you do steps 1 and 2 above. Then you begin with step 3 here...

Step 3. On your old Mac, in mail.app choose mailbox->export mailbox. You can then create a folder to export your mailbox.

Step 4. Copy the folder to your new Mac and import the mailbox to mail.app.

Steps 3 and 4 can be time consuming which is why I always use IMAP and I never delete messages from the server. This was especially handy when a failed TM restore left me with mail.app crashing whenever I tried to launch it. I finally went to ~/Library/Mail and deleted all of mail.app's folders which was about 9 gig of stuff. I then set up my email accounts from scratch and walked away. I came back in less than an hour I had all my email re-downloaded from the servers.

Hope this helps...

 

There are pages at Google that detail how to set up gmail for IMAP in mail.app. I'm a little confused by your post. Is everything you need sitting in gmail or is some stuff sitting in mailboxes in mail.app on your old machine?

If you have stuff sitting in mail.app on your old machine, you can actually import it to gmail and it will "just show up" on any computer or device that you have set up with an IMAP connection to gmail. I used thunderbird to import stuff to gmail. I had a lot of folders sitting in old eudora and thunderbird mail files and thunderbird knew how to import them. I then created a "folder" in gmail (which is actually a label). I then copied the mail from my old eudora and thunderbird mbox files and pasted it in to the new folders I created in gmail. Thunderbird automatically uploaded it and it is sitting in my gmail account now. It doesn't show up in inbox and to search it I have to specify the folder it is sitting in but I have access to over 10 years of my email from any device at any time.

Of course you could export it on one Mac in import it on the other Mac but I wanted to make you aware of this capability in gmail because once it's there, you can never lose it unless your gmail account gets compromised. Make sure you have multiple recovery options set up in case you ever have trouble logging in to gmail. The last thing you want is to get all this stuff imported only to find yourself locked out of your own account. Google does not provide real human support for regaining access to gmail. Everything is done by bots and they are not very smart, so set up your recovery options before a problem occurs. Once this is done, gmail makes an excellent "conduit" to sync email between all your devices.