Why am I receiving this error? “com.sun.mail.smtp.SMTPAddressFailedException: 553 5.7.1 : Sender address rejected: not owned by user”

Why am I receiving this error? “com.sun.mail.smtp.SMTPAddressFailedException: 553 5.7.1 : Sender address rejected: not owned by user”

 This error occurs when the email server rejects the request because the "From" address does not belong to or is not authorized for the configured SMTP account.
To resolve this, please ensure that:
  1. The SMTP username and the "From" email address are the same.
  2. The "From" address has been added and verified as an alias or "Send As" address in your email provider.