It is better to finish formal letters without any such qualifying
remarks. If you are writing to Mr. Ryan to tell him that you have a house
for sale, after describing the house and stating the terms simply sign
yourself

Your obedient Servant
Yours very truly,
Yours with respect,
James Wilson.

Don't say you have the honor to be anything or ask him to believe
anything, all you want to tell him is that you have a house for sale and
that you are sincere, or hold him in respect as a prospective customer.

Don't abbreviate the signature as: _Y'rs Resp'fly_ and always make
your sex obvious. Write plainly

Yours truly,
_John Field_

and not _J. Field_, so that the person to whom you send it may not take
you for _Jane Field_.

It is always best to write the first name in full. Married women should
prefix _Mrs._ to their names, as

Very sincerely yours,
_Mrs._ Theodore Watson.