First, check to see if your disk space is full. You can see this from your control panel. If it is, you need to clean off some space or purchase more. You will NOT receive email, or it will be sporadic if you do not have any disk space to write the email to. You may have enough space, but set your mailbox quota too low and that is what is full. Be sure to clean out your mailbox often, empty webmail trash, and have your mail client set to remove the messages from the server when they are downloaded (sometimes people have it set to keep a copy on the server unknowingly).
Also, if you are forwarding your mail to an outside email address, you ONLY need to set up the forward under "mail forwarders" in your control panel. It does not also need to be set up under email accounts - that will keep a copy on the server as well as forward your email.
