RBL Policy and Mail Delivery Failure

I was instructed by the analyst at TW/RR with whom I chatted yesterday to email
you regarding an ongoing problem (the address is invalid:  No other email address to use, so I am submitting my questions here.   I have had with my RR email account.  When I
send emails to several businesses, one being my workplace, I receive the following message copied below.  I
spoke with a TW/RR analyst approximately 3 weeks ago about this issue, and he informed me that a spam service has identified one of TW/RR's servers as a source of spam.  Emails sent via that server are therefore being blocked by the spam service.  I have spoken with the IT consultants who work with my workplace
computer network and they assure me the problem is with TW/RR and not my workplace.  The TW/RR analysts stated the same information.  This has been going on for more than a month now and is causing me considerable inconvenience.  If this cannot be corrected and is a permanent situation, I will have to close my
RR email account, take that business elsewhere, and will most likely find a replacement for my RR Internet service.  This all has to do apparently with RBL policy.

Can you shed any light on this situation? 

Subject:  Mail Delivery Failure

Priority:  Normal

Date:  Wednesday, July 31, 2013 10:40 AM

Size:   3 KB

Attachments:  [] (0.3 KB)

This message was created automatically by the mail system (ecelerity).

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:

>>> [email address deleted for security] (after MAIL FROM): 550 5.7.1 Message rejected
because of RBL policy


Re: RBL Policy and Mail Delivery Failure

This issue would depend on which server is generating the message. If generated by the work mail server, which is likely the case as other emails are getting out, the IP address of our mail server would need to be removed from the list.

Our Community Guidelines may be reviewed here.

Re: RBL Policy and Mail Delivery Failure

How do we remove your IP address? We have had this problem with our MS Exchange server at our office and it's highly disruptive to our work flow.