I want to migrate from Thunderbird 52.9.1 on an old Win7 PC to a fresh install of Thunderbird 78.13 on a new Win10 PC. Both PCs are 64-bit. I use POP, not IMAP. Because Tbird v52 on Win7 was incrementally upgraded from Tbird v2 through the years I would prefer to start with a fresh Tbird 78.13 on Win10 and then migrate over the mail and address book from v52 on Win7 to v78 on Win10. After I have completed migrating to v78.13 on the Win 10 PC and all appears to be working well I will proceed with upgrades to a more current version. The migration process seems fairly straightforward except that I am aware the format for the address book changed with v78(?). Do I need to do anything 'special' to migrate the address book from v52 into v78 and have it function properly? Will an export from v52 and then an import into v78 perform whatever format conversions are necessary for the address book to work on v78? Will a straight copy of the v52 address book file pasted into v78 work properly? Or is there something else I need to do? Thanks!