Bangla writing in Gmail has been so easy now! you don’t need to install any software for that. You will write Bangla in Gmail using phonetics. googlemail (gmail)is serving this facility now to the users…
All you need is just to make a settings that will take few seconds. You need to LOG IN in gmail. After login, go to SETTINGS at top bar of the Gmail page.
Then go to Enable Transliteration – give tick on type using phonetic English and select Default transliteration language.
If you don’t find type using phonetic English option in the Enable Transliteration, click on Show all language options. Then save it.
Then go to compose mail and click on top left corner of the formatting bar…
select অ and then start writing phonetic like AMI for আমি
select অ and then start writing phonetic like AMI for আমি
You will see the Bangla after pressing Space button on keyboard 
Hope from now, you will write Bangla in gmail
Wish your nice time with Bangla……
Wish your nice time with Bangla……
NB: If you want to read this post in Bangla, please go to blog of Rony, click here. I thank him for his post 
