+0
Hello,

I'd appreciate it if you could check the email below. Thank you in advance

Dear Professor XXX,

Hope all is well with you.

I just wanted to let you know that I'm still waiting for a letter from YYY to apply for the visa. As per ZZZ's email to me, I was supposed to receive the letter a week ago. Today, I emailed ZZZ again and asked her to follow up with the office to issue the letter as soon as possible. I will update you once I hear back.

Thank you for your time.

Best,
+1
Dear Professor XXX,

Hope all is well with you. << You don't need to say personal stuff like this. He' s not your pal (I assume).

I just wanted to let you know that I'm still waiting for a letter from YYY to apply for the visa. As per ZZZ's email to me, I was supposed to receive the letter a week ago. Today, I emailed ZZZ again and asked her to follow up with the office to issue the letter as soon as possible. I will update you once I hear back.
I assume you know that he will be interested in all these detailis.

Thank you for your time.

Best, No, too casual. He's not your pal. I suggest
Your sincerely,
Comments  
Students: We have free audio pronunciation exercises.
Thanks Clive.

>>Hope all is well with you. << You don't need to say personal stuff like this. He' s not your pal (I assume).

Is there another way to say this more formally?
You just don't need to say it at al.
When he starts to read, he just wants to know quickly why you are writing to him.

Clive