Thank You For Thank You to Landlord
Dear {Landlord},
Before I move out of the house on {street}, I just wanted to say thank you for being such a great landlord.
That house has been home for me for the past {number of} {months/years}. Not only was the place lovely, but you also always responded quickly to any issues that came up. Thank you for truly caring about your tenants.
I'm sad I have to leave, but I'm sure it won't be long before you find your next tenant. I wish you the best and I hope to keep in touch.
Sincerely,
{Your Name}