We have a redundant ISP we use when needed. However, I just got one of the strangest undeliverables I've ever seen. BROADVIEWNET.NET is our redundant ISP. We host our own exchange server in house. I switched back to our main ISP and asked the person that got this message to try to try sending again. So I may be able to add more info.
Our R-DNS record for the mail server is listed.
Your message did not reach some or all of the intended recipients.
Sent: 5/11/2005 8:25 AM
The following recipient(s) could not be reached:
RECEIPIENT NAME (E-mail) on 5/11/2005 8:26 AM
You do not have permission to send to this recipient. For assistance, contact your system administrator.
<OUR EXCHANGE SERVER #5.7.1 smtp;554 5.7.1 <static-207-188-122-93.isp.broadviewnet.net[xxx.xxx.xxx.xxx]>: Client host rejected: Please use your ISP's SMTP relay! AN00255>
Luckily this is a personal email, so I can have them help me trouble shoot.