I hate having to go page-by-page of my inbox messages and select all then delete. I wish there was a way to do all messages on all pages in one click....or at least to view them all on one page.

Is there?

'select all', click DELETE

That only does it for the page you are on. I want all messages on all pages.

No sorry, its Select All, and done page by page.  There isn't an option to delete all of them in one go.

Yeah -- chess.com.

Why allow so many messages to build up ?

For basic members, messages are deleted after 30 days, for premiums i believe its 90.

Well, it'd be nice to at least have the option to view more messages per page to expedite the process

actually i have the same problem too it has now grown to 5958 messages, most of them team invites.. there should be a faster way to delete all messages in one go..