Question

why in English informal letter writing the from address is written in left side and in some in right side​

Answer 1

$\huge\underline\mathcal\purple{AnSwEr}$

There is no fixed reason for this question. Some people prefer to write it in right side. In olden days people wrote them on right side. But now the pattern has changed,now it is written in left side.

Answer 2

$\huge\mathbb\red{Answer}$

There is no fixed reason for this question. Some people prefer to write it in right side. In olden days people wrote them on right side. But now the pattern has changed,now it is written in left side.