If you are in doubt whether to write a letter or not, don't. And the advice applies to many doubts in life besides that of letter writing.
Edward Bulwer-Lytton, 1st Baron LyttonAs a general rule, people who flagrantly pretend to anything are the reverse of that which they pretend to. A man who sets up for a saint is sure to be a sinner; and a man who boasts that he is a sinner is sure to have some feeble, maudlin, snivelling bit of saintship about him which is enough to make him a humbug.
Edward Bulwer-Lytton, 1st Baron Lytton