A complete search of the internet has found these results:
It is greatly appreciated is the most popular phrase on the web.
Both of these phrases have the same usage and meaning in most contexts. However, "It is greatly appreciated" is far more commonly used, as it is more natural to put the adverb before the final verb in most sentence structures.
10,983,332 results on the web
It is greatly appreciated whenever you bring us our mail on time.
Your presence at the wedding was greatly appreciated.
It is greatly appreciated if you keep your hands inside the ride at all times.
It would be greatly appreciated if you could bring a few people to my party this weekend.
Thank you for giving us your sincere condolences. It is greatly appreciated.
I didn't get a chance to thank you for the lovely wedding gift. It is greatly appreciated and we loved it!
198,704 results on the web
It is appreciated greatly whenever someone performs a random act of kindness on the streets.
We thank you for your continued membership. It is appreciated greatly in times like these.
It was appreciated greatly when the king visited his loyal subjects.
Did you say that it is appreciated greatly if we bring our own drinks to this event?
It is always appreciated greatly (more than just "good") whenever someone takes their shoes off in the house without having to be asked.
It is appreciated greatly by the majority of people when you dress in your unique fashion.
The show was appreciated greatly and celebrated by the unwashed masses.