Instead of

               Say

I have pleasure in informing you．．．

I am pleased to tell you／to say．．．

         Instead of

            Say

Please see that an enquiry is conducted to determine the reason.

Please find out the reason.

           Instead of

Say

Adverting to your favour
Re (your letter)
The writer, wished to acknowledge

Referring to your letter
           Or
Thank you for your letter

We are in receipt of
We began to acknowledge
We have to acknowledge

We have received

We beg to inform you
We beg to think you

We are writing to inform you
We thank you

Your esteemed favour to hand
Your letter to hand
Yours to hand

We have received your letter

         Instead of

         Say

The favour of your early reply will be obliged

I shall be glad to hear from you.

Assuring you’d our best attention at all times
We beg to remain
We remain
Awaiting the favours of your early reply

Omit all these.

        Instead of

          Say

as per                           

according  to

idem., inst., prox., ult.

name the month

if it is within our power

if we can

it will be our constant aim.     

we shall try

of even date

of today

only too pleased to              

very glad to

per

by

Please be good enough to advise us

please tell us

take an early opportunity

act promptly

yesterday’ s date

Yesterday

your communication

your letter, phone, message, etc.

your good self

you

your favor
yours of the 15th

your letter
your letter of the 15th

Under separate cover

separately, or better still,
by registered post, etc.