Recommending

[MK22]

Is the following letter grammatically correct?

To whom it may concern,
It is my great pleasure to write this letter of recommendation for Mr. XXX.
I was his supervisor for his MSC thesis. We discussed different aspects of artificial intelligence in water science during his thesis and XXX displayed analytical skills and a keen intellect. Simply put, he was a true pleasure to work with. We published different articles during our collaboration, some of more important that are listed below:
1- XXXX
2-XXXX
He was instructor and consulting professor for two students that I was supervisor for them as well. Two published paper that was more important are listed below:
1- XXXX
2-XXXX
I would rate XXX's overall performance in these subjects as great. This is evidenced by his grades and projects.
Therefore, I highly recommend that you consider XXX’s application, as He will be a great asset to your program.
In the case, any information is required. Please do not hesitate to contact me.

Respectfully submitted,

Dr. XXX

[Yankee]

Is the following letter grammatically correct?

To Whom It May Concern,
It is my great pleasure to write this letter of recommendation for Mr. XXX.
I was his supervisor for his MSC thesis. We discussed different aspects of artificial intelligence in water science during his thesis and XXX displayed analytical skills and a keen intellect. Simply put, he was a true pleasure to work with. We published different articles during our collaboration, some of the more important that are listed below:
1- XXXX
2-XXXX
He was an instructor and consulting professor for two students that I was supervisor for them supervised as well. Two more important published papers that was are listed below:
1- XXXX
2- XXXX
I would rate XXX's overall performance in these subjects as great (a little too informal). This is evidenced by his grades and projects.
Therefore, I highly recommend that you consider XXX’s application, as he will would be a great asset to your program.
In the case that any additional information is required, please do not hesitate to contact me.

Respectfully submitted,

Dr. XXX

A few suggestions.

[MK22]

Is it OK if I use excellent instead of great?

[Rover_KE]

Yes.

[bubbha]

If the letter is to an American recipient, use a colon instead of a comma after the salutation.

To Whom It May Concern:

In the US, a colon is used in formal letters (business letters, recommendation letters, letters to people you don't know, letters to people of high rank), while a comma is suited only for informal letters (e.g., to friends, relatives, and loved ones). This only applies to the salutation.