I do notknow whether this is an IOS 10bug or not but I'll describe it to see if anyone else has experienced this one.
When I go to mail and try to delete the e-mail communications that I do not want to keep, I have an intermitant bug that sends me to the web when I hit the delete button.
As I say, it doesn't happen all the time but it is annoying.
I have not investigated further yet but it might be with e-mail communications from businesses such as Amazon, Argos (I'm in the UK) etc. that display or have liks to their web site within the e-mail. Also, I am finding that the deleting process takes much longer than with the previous version of IOS i.e. 9.1.5. I get a slight delay with deletebefore the e-mail goesand a slight click before the next e-mail is displayed.