Gmail seems to be down for some time now. The mail server gives a 502 error.
The problem was reported in the gmail error reporting and support page. ( http://mail.google.com/support/ )
And they have put a red box with a message telling that they know.
Other Google partner pages would also have been affected, so Gmail for Google Apps (Business), and providers like sify.com have also been affected.
The email part of sify alone does not load. To file an error report use the sify - gmail error reporting and customer care links.
Status Update
Hope they fix this soon. This has happened previously too. And gmail has apologized about it.
Many of you had trouble accessing Gmail for a couple of hours this afternoon, and we're really sorry. The issue was caused by a temporary outage in our contacts system that was preventing Gmail from loading properly. Everything should be back to normal by the time you read this.
We heard loud and clear today how much people care about their Gmail accounts. We followed all the emails to our support team and user group, we fielded phone calls from Google Apps customers and friends, and we saw the many Twitter posts. (We also heard from plenty of Googlers, who use Gmail for company email.) We never take for granted the commitment we've made to running an email service that you can count on.
We've identified the source of this issue and fixed it. In addition, as with all issues that affect Gmail and our other services, we're conducting a full review of what went wrong and moving quickly to update our internal systems and procedures accordingly. We don't usually post about problems like this on our blog, but we wanted to make an exception in this case since so many people were impacted. In general, though, if you spot a problem with your Gmail account, please visit the Gmail Help Center and user group, where the Gmail Guides are your fastest source of updates.
Again, we're sorry.