The problem is that most normal text has words and the default behavior for a web browser is to display words unbroken.
So if you have something that’s not really a real word (like a really long email address) then the web browser just displays it on one line – and forcing the line to be as long as it needs to.
But those things are changeable in CSS. For this tiny bit of your page you’d to modify the rule, you’d like it to just break the “word” up anywhere and wrap it to the size column or screen or whatever.
If the code in question is your own, then you can add a bit of HTMLCSS to it to change the “word-break” property. It looks like this:
(this example will also not display well here on the forum – you’ll have to copy and past this to Coda or some other HTML editor to see it in action)
If it’s a 3rd party stack and your use-case is the common one (like this is supposed to be an email field and long emails are expected) then the 3rd party developer should probably add that CSS to the field.
On the other hand, if you’re (ab)using this field in a not-very-usual way – entering in a giant bit of text/code where it doesn’t really belong – then you might just be out of luck. You can’t just go willy nilly applying the “break-all” style to everything – it would make the rest of your page look crazy. If that’s the case, then I’d recommend putting it inside of column and setting a fixed size on that column – at least temporarily while you work on the page.