When you click on compose email in Gmail notice that the url changes from https://mail.google.com/mail/u/0/#inbox to https://mail.google.com/mail/u/0/#inbox?compose=new. Now when you enter say a email id [email protected] , the value for compose changes now the url became https://mail.google.com/mail/u/0/#inbox?compose=150b0f7ffb682642.
So this is working fine with my html hyperlink until the account is signed in, but if the account is not signed in it would take me the login page and when I enter the credentials somehow this compose value is lost and this does not work.