Hi @dipeshgupta , I believe you are referring to our other plugin Mail Mint and you have also emailed us with the same query.
Mail Mint is a self-hosted solution and it uses the default SMTP you have setup on your site. So using multiple email services would be something you control with your SMTP plugin. Whichever is set there will be used by Mail Mint.
As per your email, you are using WP Mail SMTP. So you may control multiple accounts from there. Here’s a doc I found on their resources that might be helpful:
Feel free to open another thread if you have more queries.
Thanks.