Q. How can I switch accounts from Nmail to another Gmail account that I use?
GMail allows for multiple accounts to be accessed thru one standard GMail Bookmark.
To enable access to all GMAIL accounts, log into your NMAIL account and then click on the down arrow next to your email address (Upper right hand corner of your screen). A prompt box will appear. Click on 'Add Account'. Type in your username and password for the additional GMAIL account(s) and press enter.
The alternate GMAIL account(s) will appear in separate tabs - keeping each inbox and labels unique to each GMAIL account.