5 reasons not to use Gmail
1. You can't all Gmail feature at all internet speed
2. At times, when you click on a mail from the list , the page keep on loading for long time.
3. Temporary failure of Gmail service at times may force you to use alternate email service provider
4.Sometimes your friend's email skip inbox to spam box for no reason
5.when you can't search previously sent message using search mail box
Hacking GMail (ExtremeTech)