Attachment size
For zMailCloud, the maximum file size allowed as an upload from your desktop to the mail server is 100MB (100,000 KB). This is both for your internal users, and from external, other mail service providers.
For Exclusive Hosting, you may define your maximum allowable file size for your organization.
In general, it's worth remembering that other mail service providers have much smaller attachment sizes, usually in the 20-50MB range. If you try to send messages over that to them, they'll reject the message.
Mailbox size
There is no enforced “cap” to your mailboxes— they can be as large as you want, and price per mailbox includes 15 GB "pooled" storage per mailbox. So for instance, if you have 10 mailboxes, you have 150GB free storage available. Extra storage is billed at thirty-five cents ($.35) per GB per month. You can also see your total storage usage in the Customer Center under Services > My Services > Metrics tab in your product details.
Included in the price of your mailbox, we must keep 2-4 times more data, sometimes significantly more, to accommodate backups.
