That's really up to you; it depends on how many people you think will be using email on your hosting account.
Most hosting providers allow you to create plenty of email accounts on pretty much any hosting plan. Keep in mind, though, that the mail you send and receive will be counted as part of your disk space quota.
With your hosting account, email can be accessed via webmail or by using a mail client such as Mozilla Thunderbird or Microsoft Outlook (shown in the background).