The main problem with Gmail is that it was impossible to have an offline version (thank you minitel 2.0).

And if you used the POP feature, on your computer or on your (smart)phone, you add to read your mails few times etc. ... Such a crap.

Thank you Gmail, after few years that we were waiting for it, Gmail finally release an IMAP feature.

And "it just works" : mails are synchronized and labels are like folders ... Thank you Google !