There is some disadvantages of using free email ids. These can be easily hacked, most people use it for spamming, received spam mail in bulk and you do not have sufficient power to stop it. Even the most benefits of such IDs is these are free.
I suppose that is the only opportunity all customers have. And that is ok. But sometimes IPS or free email service provider can block web hosting providers IPs and important emails are lost.
I see that is the only problem with free emails.