Like all other ISPs, Road Runner is interested in making sure that its customers receive all of the email that they want, while minimizing the amount of unsolicited email that gets to their mailboxes. Road Runner therefore defines the following guidelines, hereafter referred to as our "Inbound Sending Policy" for other sites wishing to send email to Road Runner customers:
Email formatting Guidelines:
Policy & Procedural Guidelines:
Road Runner's efforts to control the flow of unsolicited email into our networks could be correctly typified as reactive, rather than proactive. This means that in general, a site must violate our Inbound Sending Policy before we will start to refuse email from its servers or networks; we typically do not refuse email from sites for which we have neither direct evidence of violations of our Inbound Sending Policy nor complaints from our customers about email received.
It is also worth noting that Road Runner's efforts to control the flow of unsolicited email into our system focus on servers and networks, and not on sender addresses. This can mean that we will occasionally block legitimate or wanted email from persons who are trying to send email from a server or network from which we are currently refusing email. Unfortunately, we cannot make exceptions for individual senders using these blocked servers and networks, but we will listen to removal requests from our customers and the owners of these servers and networks, and grant those that, in our judgement, will not cause further harm to befall our network.
While the criteria we use for blocking or rejecting mail is based solely on the source of the email (i.e., the IP address of the server attempting to send the mail), our servers are also now equipped to filter email based on spam-like characteristics in the body of the mail message. The default behavior for this filtering is to place messages deemed to be spam in the customer's Junkmail folder, a folder accessible only through our Webmail product offering. Customers can change this behavior to have such mail placed in their Inboxes (with or without the subject prepended with the tag "SPAM:") or to have such mail deleted from our servers without its being read.
Road Runner Inbound Rate Limiting Policy
Road Runner imposes several rate limits on inbound mail from any given IP address. These limits include:
These steps were taken so that Road Runner could better protect its email system from abuse from malicious, compromised, or improperly configured systems. Sending systems who are affected by our rate limits will receive a 4xx series message during the SMTP transaction. This message is designed to instruct the sending system to temporarily stop sending email to Road Runner; the expectation is that the sending system in response to this 4xx message will try again at a later time to deliver its email to Road Runner. This message includes a URL directing the sender to this section of this website.
This rate limiting allows Road Runner to manage the flow of inbound email through its systems. Its intent is not to block email, but rather to control the rate at which email enters our system. If a sending system generates a volume of email during a given hour that is sufficient to trigger Road Runner's rate limits, Road Runner's inbound email systems will begin to return a 4xx series message to the sending system during the SMTP transaction (i.e., temporary failure, try again later). These limits are imposed on a per-IP basis, meaning that rate limiting will affect all inbound email received from a given IP address, regardless of the domain or domains of the senders of the messages in question.
All but the number of recipients allowed per message will vary depending on the IP's Return Path Sender Score Reputation Rank (http://www.senderscore.org/) and on whether the IP passes a Full Circle reverse DNS (FCrDNS) check. (Road Runner requires that the sending server's reverse DNS entry and forward DNS entry match; that is, the IP address connecting to our servers should resolve to a hostname that resolves back to the IP address. Should an IP address's reverse DNS, or PTR, record resolve to a hostname whose A record does not resolve back to the connecting IP, then the connection is considered to be suspect, and the rate is limited accordingly.)
If you're finding that your server is being rate limited (and the reason is not due to too many recipients per message), the most likely solution available to you will be to have the party responsible for your server apply for enrollment in our feedback loop: http://feedback.postmaster.rr.com/ Enrollment in our feedback loop costs nothing.
While our rate limits are not being published at this time (and we will not commit to publishing them) we are constantly reviewing their settings. Our goal is to have in place rate limits based around the simple theory that we want to reward IPs that tend to send mail that our customers want.
Road Runner Whitelist Policy
Senders frequently request having their IPs added to our whitelist; if you're a sender who's interested in being whitelisted here, it's important that you read this section to understand what it is that we mean by whitelisting and what benefits you might gain from whitelisting.
First, it is not necessary to be whitelisted here in order to send mail to our customers. So long as your server's IP has valid reverse DNS and is not listed on any blocklist we use, mail from your server will be accepted here.
Next, whitelisting here just means that the rate at which we will accept mail from your server will be among the highest we offer;whitelisting does not mean guaranteed delivery to the Inbox here. Moreover, since our rate limits are based on an IP's previous history and reputation sending mail here, if your IP already enjoys a good reputation here, whitelisting may offer you no benefits in excess of what you already enjoy.
Last, management of our whitelist is handled by Return Path; we use their Certified program as the source of our whitelist, so if you believe you want to be whitelisted here, you should contact Return Path.