In neetoCRM we have lead/deal/contact specific emails present by default. You don't need to connect any email account for this.For eg consider you have not synced any of your account, Go to any Lead show page -> Mails -> Send email here you'll see lead specific email in from option something like [email protected]. Any emails sent or forwarded on this email address will be associated to lead and can be seen on the lead's mails tab and also on smart mails list. Go to Mails -> Lead/Deal specific emails to see mail's list for leads and deals. For contacts we have a separate tab ie Contact specific emails .
On right-bottom page of lead's/ deal's/ contact's show page you can see email widget which consist of specific email. There is an option to regenerate this specific email as well.
We can disable this lead/deal specific emails feature ie by going to Settings -> Configure -> Lead/Deal specific emails.