You can store up to the Megabytes of storage available on your virtual hosting account. However, there may be limitations set by you specific to each POP3 account you have setup. For example, you may create an account for a friend and limit their disk usage to 1 Megabyte. This includes any attachments that may be included with the e-mail message. It is always a good idea to check your e-mail regularly. If your e-mail tests the limitation, any additional incoming e-mail will bounce and thus, will not be delivered.