I am having this same error message but on my 950xl running anniversary update (non-insider).

what to do?

How come this has never come in the latest builds yet??

this appears to work for me:

"type view local services.

Once here, stop and disable BITS (Background Intelligent Transfer Service)"

Has this ever come with the latest mail/builds?

am i missing something or did we lose the ability to select all unread mail in the Mail app?

seemd like a backward step if true. are thelNning to address this? i sent feedbback already.

thanks.