As I know it, to disable VERP, navigate to Administer > CiviMail > Component Settings and disable 'Track replies using VERP in Reply-To header'.
However, even after this is disabled, Civimail continues to send email with VERP like Sender addresses (FROM: email@example.com). The email server raised the 550 error for invalid sender.
Do I have to change some other setting to fully disable the change in the sender address? Thanks ahead.