"Two years ago I contacted you regarding the proposed sale of my property and asked for your advice regarding a number of matters. However, because of a number of circumstances over which I had no control, the property was unable to be sold until recently but during the interim you periodically visited the property, collected and removed any 'junk mail' and kept me advised.
The property was eventually listed for sale on 27 May and I was delighted to hear from you 3 days later with the news that you had sold the property. I want to thank you sincerely for your integrity and expertise, both professionally and personally, and would recommed to any future sellers they contact you with the utmost confidence that they will be well cared for from the first contact until finality.
My sincere thanks and appreciation for your patience and assistance."