If you're going to have an email account it may as well be a reasonable size. If you want huge you'd go for an Exchange account like the ones we offer with our Microsoft Office 365 product but a well managed regular email account should never fill to capacity up in a day, a week or a month.
That’s exactly why our Aztec Internet email accounts are 2Gb in size as standard and you can connect to them with either IMAP or POP3. And they are all accessible by either your email program on your computer, tablet or phone and also via webmail.
So the only question is, how many do you need?