How I fixed LMTP error after RCPT TO: xxxx 451 4.3.0 Temporary internal error

Hello, I just want to share my experience before this error: LMTP error after RCPT TO: xxxx 451 4.3.0 Temporary internal error
I had manually migrated all maildir files from another exim server to my cPanel server, but I forgot to change the ownership and permissions. So I solved it running the WHM | Email | Repair Mailbox Permissions option. Hope it could save time to somebody else ;-) Regards