salutation in letter

Dear teachers,

In the past when I wrote to my school tutor, Dr. Wayne,
I wrote this:

Dear Dr. Wayne,

but now there are more than two Dr. Wayne in the school, to specify the tutor I am writing to, I write the salutation this way:

Dr. Susan Wayne (in full name),

Is it polite to write the full name of a person in the salutation part of the letter?

Please help teachers.

Thank you.


I would not use the full name of a tutor in the salutation.

I would write this on the envelope:
Dr S Wayne.

Thank you teacher.