Export Previous Recipients - Mac Mail
If you are transferring Mac mail to another computer and want to retain all previous recipients (email autofill addresses), follow these steps.
1. Export current previous recipients. Open Mac mail and go to Window menu -> Previous Recipients.
2. Select all (ctrl + a) contacts and Add to contacts.
3. Open Contacts.app (Applications) and select all (ctrl + a) and choose Export vCard.
4. Finally, transfer the exported vCard to your new mac (vcf file) and double-click it to import contacts. You will not see all your previous recipients email