Need Help Fixing SMTP/DNS server Settings On Web Host

I have an autoresponder I set up on my server. When sending emails, I get error messages if the emails are not to "typical" google/yahoo etc emails. It says something about the dns settings. This is an example: > This message was created automatically by mail delivery software. > > A message that you sent could not be delivered to one or more of its > recipients. This is a permanent error. The following address(es) failed: > > hous-598165062[at][login to view URL] > SMTP error from remote mail server after RCPT TO:<hous-598165062[at][login to view URL]>: > host [login to view URL] [[login to view URL]]: 554 <unknown[[login to view URL]]>: > Client host rejected: rDNS/DNS validation failed. Please setup matching DNS and rDNS records: > [login to view URL] > > > > I need someone who is well versed in servers/DNS/SMTP settings to be able to tell me what's wrong and help me fix it. The email references the following link: <[login to view URL]> I don't understand those requirements, but if you can make those adjustments and make it work, this is for you. > > ## Deliverables > > 1) Complete and fully-functional working program(s) in executable form as well as complete source code of all work done. > > > 2) Deliverables must be in ready-to-run condition, as follows (depending on the nature of the deliverables): > a) For web sites or other server-side deliverables intended to only ever exist in one place in the Buyer's environment--Deliverables must be installed by the Seller in ready-to-run condition in the Buyer's environment. > b) For all others including desktop software or software the buyer intends to distribute: A software installation package that will install the software in ready-to-run condition on the platform(s) specified in this bid request. > 3) All deliverables will be considered "work made for hire" under U.S. Copyright law. Buyer will receive exclusive and complete copyrights to all work purchased. (No GPL, GNU, 3rd party components, etc. unless all copyright ramifications are explained AND AGREED TO by the buyer on the site per the coder's Seller Legal Agreement). > ## Platform > > php smtp, linux, dns