TB doesn't have a resend feature the way you're describing it. Maybe you could create something like it with the scheduler.
Add all contacts for whom you want to enable this feature to a new address book group called 'Resend' (Note that a contact can belong to multiple non-trelated address book groups, don't create multiple entries for the same address.)
Create a color goup with the name 'Resent'

Create a read filter that checks whether the message doesn't have the colour goup 'resent and that the recipient belongs the address book group 'Resend'. Set the action for this filter to forrward the message and set the template for this action so that it sends the message to the original recipient. As second action let it set the message to colour group 'Resent'.
Create a schedule in the scheduler that runs this filter every five hours. That won't resend your message after five hours, but it'll resend it within five hours.

Create an outgoing filter that checks whether the message is a forwarded message and if so then add it to colour group 'Resent'. This is to prevent your resent messages to be resent again.

If you really want to resend it after five hours you need to be somewhat creartive and add a couple of colour groups and matching filters.

Off hand I can't think of a better way to automate resending your messages. I can think of other ways, but they're just as complicated.