Backup and restore Mails

[kinetos]

Hello, I've installed El Capitan on my Mac Pro 2,1 All is allright excepted Mail...
I've tried to backup com.apple.mail folder and Mail folder from Yosemite and nothing... When Mail is open, he ask me to create a new account... Have you some idea to help me?

 

[dianeoforegon]

Hello, I've installed El Capitan on my Mac Pro 2,1 All is allright excepted Mail...
I've tried to backup com.apple.mail folder and Mail folder from Yosemite and nothing... When Mail is open, he ask me to create a new account... Have you some idea to help me?

With Mail quilt...
Delete the com.apple.com folder in Containers. This does not contain your messages.

Go to System Preferences > Internet Accounts and uncheck Mail in each account.
Open Mail > Select to add accounts.

Mail data is now in the V3 folder in your Mail folder.

User's Library/Mail/V3