Does this count as defamation

[singularity]

What is the name of your state (only U.S. law)? NC

If a parent writes a letter to a principal's boss insinuating an improper relationship between the principal and another student (easily proven to be untrue) can that parent be sued for defamation?

 

[LdiJ]

What is the name of your state (only U.S. law)? NC

If a parent writes a letter to a principal's boss insinuating an improper relationship between the principal and another student (easily proven to be untrue) can that parent be sued for defamation?

Possibly...the info is vague.