Error 553, Sending a newsletter...help?

[joetry]

Hello, I am trying to send an HTML newsletter from my website. My hosting company is ipowerweb, and I am trying to use the program PC iMail 2006. I am trying to use this program because A) it allows you to set how many emails are sent in x amount of time. For example 5 emails in 30 seconds ( This would help with the fact ipower limits you to 100 emails an hour ) and B) It does not list every e-mail in the "To:" section, so each user will only see their own email, and noone else's. The problem here is that I get an error most of the time when I try to use this. "The server rejected one or more recipient addresses. The server response was: 553 sorry, that domain isn't in my list of allowed rcpthosts (#5.7.1)" Here is a link that might help get an idea of why this error message might occur: http://helpcenter.ipower.com/cgi-bi...ated=1086149087 This helps outlook maybe, but there are no setting like that on PC iMail 2006, so it is not much help to me...but PC iMail 2006 does use SMTP so that could be the problem...but PC iMail 2006 has worked on and off...just mostly off for some reason..so II know it can connect... also ipowerweb uses "vdeck" if that helps.. Does anyone here have any ideas for me on what the problem is here, or even a better idea for sending out newsletters from my site ? I need them to be sent from my sites email, and not show all users email addresses to one another. I would appreciate any ideas on what I should try. Ipowerweb says they host over 500,000 websites, so I would imagine someone has to be running a sucessful newsletter from there... Thanks, Joe