Dear [Customer's Name],

Today is a special day, and we couldn't let it pass without sending our warmest wishes to you on your birthday!

As a token of our appreciation for being a valued customer of [Your Company Name], we have a birthday surprise waiting for you:

[Offer Details - Discount, Free Gift, etc.]

This special treat is our way of saying "Thank You" for choosing [Your Company Name]. We hope it adds a touch of joy to your birthday celebration.

To claim your birthday surprise, simply use the promo code [Promo Code] at checkout.

Thank you for allowing us to be a part of your special day. We wish you a fantastic birthday filled with happiness and joy.

If you have any questions or need assistance, please don't hesitate to reach out to our customer support team at [Support Email/Phone Number].

Best regards,

[Your Name]

[Your Title/Position]

[Your Company Name]

[Your Contact Information]