Road Runner's Block Lists
Road Runner makes use of multiple lists of addresses and networks
from which it will refuse email.
Two lists are maintained by Road
Runner, and their content is based mostly on complaints from our
customers of spam received from the entity being refused. We also
use several third-party lists, as discussed below.
The two lists maintained by Road Runner are as follows:
- Name-Based Block List - IP addresses map to names, such
as 'mail-server.foo.com', or 'ip_address.reverseIP.bar.net'. Road
Runner's name-based block list is comprised of two kinds of name
patterns:
- Those that Road Runner knows or believes to be indicators of
other domains' dynamic address space (e.g., dialup or residential
broadband customer space)
- Generic name patterns that may be used for other providers'
static address space (e.g., permanently assigned IP addresses)
but that give no indication as to the name of the domain that
is using the IP address.
Senders using IP addresses blocked due to this list will receive
error messages that look like the following:
If you find yourself in this situation, either route your outbound mail
through your provider's mail servers or contact your ISP or hosting
provider and request that they change the PTR record for your IP
address to a non-generic name.
- IP Address-Based Block List - This list is comprised of
IP addresses and networks from which Road Runner customers have
received unsolicited mail about which they have complained to Road
Runner. Senders using IP addresses blocked due to this list will
receive error messages that look like this:
554 5.7.1 - ERROR:
Mail Refused - <IP.ADD.RE.SS> - See http://security.rr.com/mail_blocks.htm#REASON_CODE - YYYYMMDD
If you find yourself in this situation, you can
request removal.
Note:
The above error messages are just templates that show the format
of an error message that indicates a block put in place by Road
Runner. Actual error messages would replace 'DOMAIN_NAME' with an
actual domain name, 'IP.ADD.RE.SS' with an actual IP address or network
address, '#REASON_CODE' with a tagged code
directing you to a URL on this page, and the optional 'YYYYMMDD' with
an eight-digit number signifying the date that the block was put into place.
Third Party Block Lists
The third-party block lists we employ are as follows:
Error messages resulting from an IP address being in any of the
third-party lists used by Road Runner will look like this:
- Cloudmark Sender Intelligence
554 5.7.1 - ERROR:
Mail Refused - <IP.ADD.RE.SS> - See http://csi.cloudmark.com/reset-request/
- SpamHaus ZEN
554 5.7.1 - ERROR:
Mail Refused - <IP.ADD.RE.SS> - See http://www.spamhaus.org/query/bl?ip=IP.ADD.RE.SS
- MAPS RBL-Plus
554 5.7.1 - ERROR:
Mail Refused - <IP.ADD.RE.SS> - See http://www.mail-abuse.com/cgi-bin/lookup?IP.ADD.RE.SS
- Return Path Sender Score Blacklist
554 5.7.1 - ERROR:
Mail Refused - <IP.ADD.RE.SS> - See http://sendersupport.senderscore.net/
If the error message you're receiving references one of these
external lists, go to the website to which the error message is
directing you, and follow their policies for requesting removal.
Unresolvable DNS for IP Address or Sender Domain
In addition to these block lists, Road Runner's mail servers will also
refuse mail from IP addresses that either have no reverse DNS, or PTR,
record, or that have a PTR record that is unresolvable, and from email
addresses in domains that do not resolve. Those error messages will
look like this:
-
554 5.7.1 - Connection refused. IP name lookup failed for <IP.ADD.RE.SS>
-
421 4.7.1 - Connection Refused. Cannot resolve PTR record for <IP.ADD.RE.SS>
-
554 5.1.8 - Domain of sender address EMAIL.ADD.RE.SS does not exist
-
421 4.1.8 - Domain of sender address EMAIL.ADD.RE.SS does not resolve
If you are a sender finding your mail refused due to either of these
reasons, you should contact your ISP or hosting provider to either get
a PTR record configured for your IP address or for technical support for
the proper configuration of the 'From' setting for your mail client
software.
Interpreting Error Codes
Any error code that starts with the number 5 indicates a permanent
refusal of the INBOUND mail message; the sending server will inform the
sender of the email that his/her message has been rejected, and the sending
server will discard the message.
Any error code that starts with the number 4 indicates a temporary
failure of the INBOUND mail message. This means that Road Runner
has had to temporarily refuse mail from that source due to one or more
reasons. The sending server will queue the mail for later
delivery attempts to Road Runner. Depending upon how long it
takes for the problem to subside, the sender may receive a
notification from the sending server that the message has been
delayed, and in extreme cases, the sending server may give up
altogether on the message and return it to the sender. It
usually takes several days for such a failure to occur, however,
and the problems causing temporary refusal usually subside in a
matter of hours, not days.
Note: "Permanent" in the case of a mail error does not
mean that Road Runner has blocked mail from the source "forever".
"Permanent" in this case indicates a "go away" response to the
mail message, as opposed to a "Temporary" error, which means
"try again later".
How To Get Unblocked
If you are being blocked due to a listing on Road Runner's IP
Address-Based Block List, you can use
this website to request that the block be lifted.
More information about the specifics behind each kind of block
can be found below. The section
specific to your error message may be worth a read before you
request removal.
If you are being blocked due to a listing on Road Runner's Name-Based
Block List, do not use the removal request form, as it will not help
you. Instead, contact your ISP, hosting provider, or IT department as
appropriate, and start the process of getting your mail server's IP
address a PTR record that is non-generic.
If mail from your server is being refused because the PTR record
for its IP address is non-existent or unresolvable,
contact your ISP, hosting provider, or IT department as appropriate,
and start the process of getting a PTR record properly configured for your
mail server's IP address.
If the reason that you're having your mail refused by Road Runner is because
your server appears on any of the third-party lists we use (the error
message you're receiving will give you this information) you will need
to contact the third-party provider of the list in question.
Note: It is possible, under limited circumstances, for Road Runner
to override a listing of a third-party list; those circumstanaces would
include, but are not necessarily limited to:
- A demand from a sufficient number of our own customers to lift the block.
- Evidence from the listee's provider of a good-faith effort to get the
listing removed.
- A willingness on the part of the listee and the listee's provider to
accept any complaints about the space in question from Road Runner and to
take action based on those complaints.
If you feel that you meet these criteria, please contact us at
If you're not sure if you're being blocked, or if you don't have
an error mesage in hand, you can either
see for yourself if your mail server's IP address is blocked,
or you can send email to
blockinfo@postmaster.rr.com. Include in this message as much
information as you can regarding your situation, so that the Road
Runner Postmaster Team can begin to investigate your situation.
Please include a valid reply address so that a member of the
Postmaster Team may contact you if need be.
For faster access to your specific error message, click on the
link below that matches your reason code:
554 5.7.1 - ERROR: Null sender with multiple recipients not allowed here
The RFCs require that we accept mail from the NULL sender (i.e.,
"<>") because Delivery Status Notifications (DSNs) are typically
sent using that sender address, and we do accept mail from the NULL
sender so long as it's addressed to only one recipient.
This error message is an indication that a message was presented to
our inbound servers with a NULL sender and multiple recipients; we do
not accept such mail in this case. Our rationale is as follows:
- Messages from the NULL sender are usually DSNs
- DSNs are sent in response to a previous message
- A message can only ever have one sender, therefore
- A DSN should never be addressed to more than one recipient, because
the message in response to which the DSN is being generated could
only have had one sender.
The most typical legitimate sender who would be affected by this rule
would be what we'd term an amateur bulk sender, someone running some
sort of home-grown mailing list application that's sending to multiple
recipients at a time using the NULL sender as its "From" address.
The solution is for the application to be altered so that it's not
doing that.
