A relay error can occur if you're using a laptop through a non-supported provider such as AOL or MSN. The best solution in this case is to use webmail (http://mail.websitehosting.net) to check your mail while on the road.
Another cause could be that you do not have your mail client set to "This server requires authentication". Our mail server requires you to authenticate to our servers by first connecting to the mail server to check mail before sending mail. This ensures you have a valid e-mail account on our servers and are not a spammer.
Please reading the following article for more assistance:
http://www.websitehosting.net/knowledgebase.php?action=displayarticle&catid=1&id=31
