When introducing the new Facebook Messages system last week, Mark Zuckerberg pressed on that it would not be an email service: email would ‘only’ be part of the new messaging system which uses several other channels to communicate. No more, no less. Even so Facebook has launched a new postmaster subsite at http://postmaster.facebook.com for future deliverability reference and issues/questions. The page includes the following points relevant for bulk email senders:
– Facebook does not accept unsolicited bulk mail.
– Facebook only accepts bulk mail from highly reputable sources and does not offer support for any issues encountered.
– Facebook encourages brands and organizations to communicate with its users via Open Graph publishing instead of email.
Next to that Facebook will use DKIM for identification with outbound email, including separate services and IPs for suspicious email. Facebook notes the following about that:
Why have IP Addresses for suspicious mail? Shouldn’t you just refuse to send it?
Facebook applies filtering to all messages submitted by users. If we are confident that a message is abusive, we refuse to deliver it and take appropriate action on the user’s account. However, some messages fall into a gray area and we deliver them but mark them as spam. If any of these gray area messages are destined for other mail systems, we route them out of a set of IP Addresses dedicated to such traffic as a signal to other administrators. We also add ‘X-Spam-Flag: YES’ to the message header and DKIM sign them as spc.facebook.com. Facebook encourages the administrators of other systems to treat these messages with an appropriate level of suspicion by delivering them but marking them as spam or by taking whatever other actions they feel are appropriate.
For inbound email, Facebook mentions the use of SPF and DKIM in the reputation and authentication department:
How does my Reputation affect email delivery?
The behavior of mail server IP Addresses, authenticated domains, and URL’s are tracked. Consistent bad behavior will lead to mail delivery issues. Consistent good behavior will reduce mail delivery issues.
How does my Authentication affect email delivery?
Facebook requires either SPF records or DKIM signatures to authenticate mail from your domain. Unauthenticated mail may be delivered at a slower rate than authenticated mail. Recipients may see warnings that the source of the message could not be verified when reading unauthenticated messages.
This is all pretty serious (and a good thing!) which means Facebook will be taking email pretty serious on the deliverability front: no second guessing for ESPs and ISPs trying to get through to Facebooks Messages system for delivering email. Let’s just hope that as usage and volume gets ramped up, the ‘does not offer support on issues’ part gets dropped to ensure maximum cooperation between the sending and receiving systems.