I'm using Chrome version 66.0.3359.181 on Windows 7 with the latest X-notifier 4.2.2.
When I get an email, the notification icon shows up, but when I click it, it opens three tabs of the same account. This amounts to six tabs total if I get emails for two of my email accounts.
This issue doesn't happen on my Surface, which uses Windows 10.
I've heard that this was an issue before?
Just sayin'...
I'm also using Chrome version 66.0.3359.181 with the latest X-notifier 4.2.2... but on Windows 10 Pro ...and not having that problem. When I clicked my pop-up notifications, it only opened new mail tabs once for each account.
Problem is fixed.
It's working now. I didn't do anything (I think?) but there's no more multiple tabs.