Reporting Email Delivery Problems

Please read the following instructions and fully complete the form.

If you received a bounce message like the one below it is an indication that the IP address of your sending server has been blocked from delivering to us or our customers you may request to have it unblocked here. Please copy and paste the entire contents of the “bounce” or “Delivery failure” message you received in email. You should have received a message like:

Unsolicited e-mail from refused by CompanyV. See

The numbers “ “ in the message above is the IP address of the sending server. If you are aware of additional send servers for your email please include those IP addresses as well. Please Fill out the form carefully! PLEASE copy and paste the ENTIRE bounce message you got back! We require the email address you were sending to in order to inform them and you when resolved. If you did NOT receive a bounce message like the one above, we are probably NOT blocking your mail but your mail may have ended up in a users junk folder. Please call the person your were sending email to and let them know about this!

The form to the right is to be used if you are sending email to one of our customers – or you are one of our customers.

Request allow to send to our servers

PLEASE INCLUDE ENTIRE BOUNCE MESSAGE – If you do not accurately complete the form below there will be a greater delay in response.

Sender Allow Request

5 + 6 =


What is an IP Address?

An Internet Protocol address (IP address) is a numerical label assigned to each device connected to a computer network that uses the Internet Protocol for communication. An IP address serves two principal functions: host or network interface identification and location addressing. IP addresses resolve to the named servers or services – for example must have an IP address assigned in DNS for other servers to find it.


How many domains can share an IP address?

THOUSANDS of domains and services can share a single IP address

A study way back in 2003 stated that sharing of IP addresses was prevalent and used by 87.3% of active COM, NET, and ORG web sites. In addition, IP sharing is substantial: More than two third of active COM, NET, and ORG web sites share their respective web servers with 50 or more other web sites.

Today I can assure you the numbers are much much higher, for bad IP addresses I have seen 1200 to 1600 as almost average numbers on really inexpensive shared hosting services.


We apologize for the inconvenience and we are probably not specifically blocking YOUR email. We block email if mail coming from an IP address is either persistent spam or contains virus that could harm our customers. Many service providers maintain many many mail servers that are shared with many many customers. All it takes is one customer doing bad things or one innocent customer with an infected machine for a server to get blacklisted. If we see a trend of many IP addresses in a defined range that are all causing an issue we may just block the entire range to slow the flood.

Why it may seem that we are inconsistent with blocking email

From a customer of one of our customers:

Your system is inconsistent in its rejections.

There is a very good reason for this! We had an issue recently that I will use as an example. The customer of one of our customers uses VERIO as the ISP for email. We were blocking email and they received a bounce message. We do realize how important the ease of communication is to both our customers and the customers of our customers. The new IP address you informed us of was we made sure was NOT blocked. The email that came through was routed through the ip= The NEXT bounced mail was sent through another IP address Unsolicited e-mail from [] refused by CompanyV.  See The reverse for the NEW IP address provided that we made sure was allowed is:  but there are 8 IP addresses with the same reverse name and of the 8 we were blocking 1   Verio has  65,534 IP addresses in the /16 range managed by The Endurance International Group ALL of the 28 addresses I checked are on public blacklists (outside of our system) which means the service provider is  not monitoring outgoing mail nor are they maintaining the health of their IP addresses  – or there are infected machines so I am not comfortable setting more allows. I am unsure what VERIO recommend the customer use for outgoing mail server (SMTP) but if it is  we were NOT blocking that specific set of 8 IP addresses.  Due to the high volume of spam and virus reported through their networks I cannot guarantee we would not block it in the future. The following is a report only on the IP addresses with reverse to The following excerpt is from an article from 2014 regarding The Endurance International Group. The time and costs for both companies and individual users filter through spam and virus is enormous. Small and large businesses are always looking for the most cost effective way to maintain web presence. Just like real estate location is important and to business visibility is vital. With all of the “Do It Yourself” options for putting up a website of course the next question is how much per month? At that point the non-technical are simply going to go with the cheapest as long as it gets the job done. With the amount of outsourced IT for web presence there are many areas of hosting services that are mystifying to actual owners of businesses. And they do not have time to learn a whole new set of buzz terms and acronyms to get up to speed – they hire folks to do that. They shop for cost savings there as well. What amazes me is the cost of the cost savings. A little bit here and a little bit there adds up over time and even though there are perceived cost savings this big ugly machine is running behind the scenes. And the machine is mighty! When we (CompanyV) block an email from a spam provider we actually send a response back – most blacklisting services do not. What this means to our customers is that the people attempting to communicate with them, who may be on a bad provider, are made aware that the mail the was not delivered. Many times we will investigate and set an allow for the sender. Sometimes the IP address they are sending from as been sold to a different company and its reputation has been cleared or can be cleared. How does an IP address make it to a CompanyV blacklist?

  1. We monitor the incoming mail servers and have accounts that a spam traps that we monitor for unsolicited mail.
  2. We run a Bayes database and learning systems to scan for spam patterns.
  3. We run Virus scanners on all incoming mail and investigate senders of virus mail.
  4. Our Customers can report spam and we investigate senders and block per requests.
  5. We subscribe to public databases of reported spammers.
  6. We monitor and track bad hosts that do not respond to abuse reports and that continually host spammers.

Who are bad hosts? There are a few service providers that are major players in hosting spam and virus senders. We are unwilling to set allows for mail coming from senders because they have policies and practices that threaten the safety of our customers. A recent flood of spam has been coming from companies selling services that allow relays from other countries that have already been blacklisted. Many of these companies sell reseller agreements to unsuspecting web services and small hosting and web designers. The Endurance International Group has been buying small and large hosts who have provided inexpensive hosting to a large audience. Bluehost and Hostgator for example were highly regarded provider for WordPress hosting but when these companies were absorbed by Endurance InternationalGroup service response time became problematic and mail services are now distributed over many many many servers and responses to abuse requests are rarely responded to. This creates massive problems for people whose services are with these hosts. An important note – MOST service providers will not even indicate that mail has bounced if they detect it is coming from a blacklisted server. Endurance International Group, Inc. (EIG), formerly BizLand, is one of the world’s largest website hosting companies. The company was founded in 1996 and is headquartered in Burlington, Massachusetts, managing over 2.9 million customers and 10 million domains. It achieved its size by acquiring a large number of smaller hosts, which it continues to operate under the original names. In 2011, Endurance was bought from Accel-KKR by Warburg Pincus and GS Capital Partners, for around $975 million. Warburg Pincus, LLC is an American global private equity firm with offices in the United States, Europe, Brazil, China and India. In addition to the services problems presented about EIG there are other players that we consider to be bad hosts. Among some of the worst are services supplied by:

  • Digital Ocean, Inc.
  • Services on
  • LiquidNet Ltd
  • Continuum Data Centers
  • MadeIT inc. MADEITINC
  • softlayer

We are unwilling to set allows for servers that managed by service providers that will not take action on abusive behavior. If you are trying to send email to one of our customers you can send us the bounce message and we will review and respond! If we are blocking email coming into our services we will investigate and set an allow as long as it does not put our customers at risk.