Q: why my gmail is not working?

How should we know? You've provided absolutely no information on which anyone here could even begin to base an answer.

same here, gmail IMAP now takes forever to sync with the mail client, and not just Mail, but the slow-sync also happens in Thunderbird. perhaps Google's having imap server issues... i've given up on the Mail client, too unreliable, i just use the browser instead.

For me ... specifically ... gmail simply is only sporadically downloading on my iMac with Mavericks 10.9.1. Currently looking at mail that is 2 days old.