Salefreaks helpdesk system will help you manage your communication with buyers easy.
The interface will allow you to filter the messages and to prioritise all messages according to importance.

For example- you can filter messages from paying costumers (post-sale) and when you finished this messages to take care of not yet paying customers (pre-sale).

After you clicked the ticket/message you can easily reply the buyer, you can also choose from your reply templates.