Unfortunately I have tried both of those and found them both wanting.
Actually I don't agree with assessment of email but only because I am coming from it as a work tool rather than a personal thing. While I agree that a lot of personal messages are sent via other means, work is almost exclusively carried out via email.
The problem here is the ever present Outlook I would imagine coupled with bespoke clients for some bigger companies.
Interestingly, I would be prepared to pay a reasonable amount of money for a good email client as it isn't something that I would expect to be free.
when i using all website this error message displayed in my opera browser
Unfortunately, something has caused this page to quit. It might have been an extensions conflict or some other reason."
Do you use any extension? If so try disabling all of them to see if the problem goes away. If so, re-enabled the extensions one at a time to try to find which one is causing the issue.