Hi @xtianu
Unfortunately, I cannot give you a silver bullet here.
SPAM categorization is a bit of a black box as many factors go into it, every email provider does it differently, and also email clients may do their own SPAM scoring additionally. And of course, nothing is transparent.
Keep in mind that for many hosting environments where you share a server / IP address with other sites, the SPAM scoring also depends on what everybody else is doing. Not sure if that could apply for you, though.
As a general tendency: you should be using the mailing list address as the FROM address. This usually improves deliverability, but if it really improves with SPAM scoring, I am not sure.
Hope that helps.
