How to delete ALL e-mails from an account

[#1]

My husband, Edward, passed away several months ago.  I'm just now getting around to figuring out what he left "in the cloud".  I discovered yesterday that his Verizon.net e-mail account contains close to 30,000 e-mails.  I want to delete all of them, but Verizon segregates the e-mails into pages of 30 each, so when you click the page checkbox, then click Delete, it only deletes the 30 on that page.  That means I would have to repeat this 1,000 times, which I'm not about to do.  I can find no way to delete ALL e-mails.  Is there a way to do that?

[#2]

30 messages displayed is the default, but you can change that.  On your email page, under "settings" is an option to change the number of messages per page.  One  option is "no limit."