Can a pay rent or quit form be delivered by registered mail in VA or must it be served?

Can a pay rent or quit form be delivered by registered mail in VA or must it be served?
No registered or certified mail... personal service or posted on the unit door AND a copy sent regular mail. You can send USPS delivery confirmation if you wish.

And if it was me, I would hire a personal service to do it, even if they post it on the door, that way you have proof to use in court, the statements from the process company