The 6515 on the latest firmware works just fine with Gmail.
If you are on the latest firmware and getting a login failure I would have to assume you have 2-factor auth enabled in Gmail.
This problem is also affecting the Color 560 and D136 models. Both scan just fine with a "regular" Gmail account with lowered security set, but neither will work with Google Apps for Business. Just an FYI to Xerox.
Several posts have been discussing the recent changes in the Gmail security parameters and the issues it is causing with their multi-function devices. We are hoping this information will get you scanning once again with an alternate method while the email issue is being researched.
This focuses on the WorkCentre7120 7125 product family in relation to the scan to email feature with Gmail in which the Xerox device produces different error and fault codes relating to communication.
Recent changes in Gmail security parameters have changed the authentication requirement which is causing the Multi-Function Printer to have authentication failures. Gmail has two open Authentication methods (OAuth and OAuth2).
To isolate the cause of your errors and confirm if the issue is the Gmail server authentication, please use this test which will take you through each of the steps. If the telnet test fails as outlined, then the options are to install scanning to a network folder or to a mailbox (folder).
These instructions are intended for an advanced user.
The Gmail Scanning Issue document also includes step by step (all with screen shots) on other forms of scanning the device supports (essentially alternative methods).
The issue is now in Engineering and a possible resolution is being developed but supplied in the linked document above are alternate methods of scanning for customer use.
NOTE – This does not address or outline the use of any other ”free” email providers.