I am looking for a good hosting program with good emails. I would like to know how big the each email account can be and how big the incoming email attachment can be. Thanks!

The email account is limited only by the amount of disk space in your hosting plan. I've never had a problem with incoming attachment size, though I know there's a 2 or 3 MB limit on outgoing attachments. At least in the Webmail program (there are other email options).