When I first learned about RIM’s BIS IP address SPAM scoring system I was curious to learn more. I pinged a few contacts and they did not have any more details. Luckily enough RIM has released a document that details a bit more about their SPAM system called “BlackBerry hosted address is unable to receive email messages from particular domains.”
It turns out that this spam system is only for BlackBerry hosted addresses which I think means the @carrier.blackberry.net address RIM gives you though I have not been able to confirm it. This anti-SPAM system sits in front of RIMs SMTP servers and based on the reputation and behavior of the sender it assigns originating servers a score from –10 to +10. The higher the score the better reputation the server has and the more leeway it gets in sending different types and quantities of messages.
Some server admins may notice that they have problems sending large quantities of messages to BlackBerrys through forwarding or distribution lists. They will get a SMTP response code starting with 554 or 421 or an error like “Too many recipients.” RIM does not offer any way around this but at least they offer admins a way to check if this is the problem.
You can read the whole document below or at this link.
BlackBerry smartphone users cannot send or forward large numbers of email messages to BlackBerry hosted email addresses from a particular domain. These email messages are not delivered to the BlackBerry smartphone; however, single email messages sent from the same domain are delivered successfully.
BlackBerry Internet Service hosted email addresses are protected by an anti-spam system. This system sits in front of the BlackBerry Simple Mail Transfer Protocol (SMTP) servers. It uses a scoring system, based on the reputation and behavior of the sender, to determine possible spammers and take appropriate action against them. This system assigns originating messaging and collaboration servers a score between -10 and +10; higher scores correspond to a greater reputation, and thus more freedom in the types and quantities of messages allowed from that messaging server.
As a result of this system, messaging servers may experience difficulties in sending a large volume of messages to BlackBerry hosted addresses through forwarding, distribution lists, etc. In particular, SMTP logs for the originating messaging server may show SMTP Response Codes beginning with 554 or with 421 or others, indicating that there was a problem with email message delivery. They may also show error messages, such as Too many recipients, or just a failure to send certain email messages to the desired hosted email addresses.
This behavior may be caused by the anti-spam system restricting email messages sent from certain email messaging servers, due to a low reputation score. This may result in connection throttling, limiting the number of connections a messaging server can make to SMTP servers before being rejected, or limiting the number of recipients that can be sent to simultaneously.
There is no formal resolution to this issue because this is the way the system is designed to function. However, most administrators should be able to determine the changes that need to be made to their systems to accommodate the spam system.
In order to assist in the diagnosis of this issue and provide additional information, complete the following:
- Collect the following information:
- SMTP logs of the affected messaging server (ensuring that the error message received is noted in the logs)
- IP(s) of the affected messaging server (ensuring that the collected IP is responsible for relaying email messages)
- Email message domain affected
- Non-delivery receipt (NDR) or bounce back message of the rejected email message, if one exists
- Perform a Telnet session to each of the following MX records:
- mx01.bis.<region of carrier>.blackberry.com
- mx02.bis.<region of carrier>.blackberry.com
- mx03.bis.<region of carrier>.blackberry.com
- mx04.bis.<region of carrier>.blackberry.com
To perform these sessions, type telnet <mx entry> 25. For instance, telnet mx04.bis.<region of carrier>.blackberry.com 25.
- Proceed with the SMTP process (helo, mail from, rcpt to, data).
- Copy as much of the process as possible into a text file.
- Document the time stamps, along with the time zone, for this process. The tag <region of carrier> is a two character value that specifies the region the service provider is located in, for instance, na for North America, ap for Asia-Pacific, and eu for Europe.