You're failling to understand one thing i think:
An e-mail address doesn't take up that much space. Therefore, you cannot truly define a limit for these. I prefer the word unmetered for e-mail accounts, sql accounts, etc...
But yes you can offer them, when what you're trying to say is:
'You can use as many of them as you need within your allotted account space'
For example, someone could have 3000000 email accounts, but if they check them every minute and delete them (like i do) they aren't going to take up hardly any space.