I don't know how to end my letter of gratitude to a university teacher

[Hana6]

If I want to thank my teacher on facebook for accepting my friend request. I don't know whether I have to end it by regards, kind regards, best regard or any other word? I just want to sound polite.

 

[Tarheel]

If I want to thank my teacher on facebook for accepting my friend request.

You might want to make that a sentence.

I don't know whether I have to end it by regards, kind regards, best regard or any other word? I just want to sound polite.

How about:

Thank you for accepting my "friend" request.

Best regards,

XXXX
​

(I am not a Facebook user.)

 

[MS3330]

How about:
Thank you for your kind consideration of my friend request.

 

[Raymott]

How about:
"Hi <name>,
Thanks for accepting my 'friend' request!
Hana6."

Is it really necessary to make such a fuss over a friending on facebook?

 

[Barb_D]

How about:
Thank you for your kind consideration of my friend request.

No.
As was recently noted, using "kind" is a marker of a non-native speaker.

That aside, if the teacher has accepted, the "consideration" is in the past.