Every time you send an email, you have a great opportunity to promote your property at absolutely no charge, and it is so simple.
John Romano of the Vacation Rentals Community suggests using the Outlook signature function to add a personalised footer that you can attach to every email. His post includes instruction on how to do this. You can even attach an image so you could have different photos for each season. There is no end to how creative you can be but remember to keep it simple.
I also use this function to create brief email responses in answer to common questions. For example, if you consistently get the same question, you can write a standard reply and store it in your signature file in Outlook. When you need the response, open a new message, click on the signature file, and select the message you want. Voila!