When you sign up for email hosting, you must select a multiplier of 10 or 25 GBs per mailbox. The storage multiplier is used to generate your total plan storage, i.e., Total Mailboxes x Storage Multiplier = Total Storage.
For example, if you sign up for 30 mailboxes with 10 GBs per mailbox, you get 300 GBs total storage. What this means:
- You are not locked into 10 or 25 GBs per mailbox.
- Mailboxes can be allocated any storage limit from 1 MB to Unlimited.
- You can set all users to “Unlimited” quotas and not worry about total storage until your total actual, used storage is at or near 300 GBs.
For POP3 users downloading messages off the server, storage will generally not be a big concern. Similarly, IMAP users should periodically archive/move messages from the mail server to their primary local mail client to avoid server storage accumulation. For example, in Thunderbird, IMAP users can specify an “Archive” folder under the “Local Folders” account, not as a subfolder of the IMAP server account. Check out this article for more information on the difference between IMAP and POP3.