Springs Hosting offers two protocols when checking for mail: POP and IMAP.
Using POP, your email is downloaded from the server by the mail client (ie. Outlook) with the ability to keep a copy on the server. When you don't choose the option to leave a copy on the server the mail is then deleted from the Springs Hosting server. If you do leave a copy on the server the mail can be retrieved later or by an additional device.
It's important to note that POP is the most basic protocol and doesn't have the ability to mark items as read if you keep a copy on the server. It also doesn't offer the ability to sync mail between devices.
With IMAP, you mail syncs between the client(s) and the server. Mail syncing keeps track of read, unread, sent and deleted mail across all devices. IMAP mail is really nice but it does have some caveats.
Email accounts are stored in your hosting plan and share that space. If your hosting account is out of space, any incoming mail will be rejected by the server. It's also worth noting that some email clients encounter issues when dealing with larger mailboxes.
POP and IMAP are intended for basic mail functionality. If you are looking for enterprise level email accounts, ask us about Office 365. Office 365 offers 50GB of space per account, shared files hosting, HIPPA compliancy and much more.