M3AAWG Recommends TLS

SSL or Secure Sockets Layer is protocol designed to provide a secure way of transmitting information between computer systems. Originally created by Netscape and released publicly as SSLv2 in 1995 and updated to SSLv3 in 1996. TLS or Transport Layer Security was created in 1999 as a replacement for SSLv3. TLS and SSL are most commonly used to create a secure (encrypted) connection between your web browser and websites so that you can transmit sensitive information like login credentials, passwords, and credit card numbers.
M3AAWG published a initial recommendation that urges the disabling of all versions of SSL. It has been a rough year for encryption security, first with Heartbleed vulnerability with the OpenSSL library, and again with POODLE which stands for “Padding Oracle on Downgraded Legacy Encryption” that was discovered by Google security researchers in October of 2014. On December 8, 2014 it was reported that TLS implementations are also vulnerable to POODLE attack, however unlike SSLv3, TLS can be patched where as SSL 3.0 has a fundamental issue with the protocol.

Due to a number of known security issues with SSLv2 and SSLv3, M3AAWG urges the industry to disable all versions of SSL.

M3AAWG are not the only ones calling to leave SSL behind, Firefox disabled all versions of SSL in Firefox 34, Microsoft will disable fallback to SSL 3 in IE11 starting in February 2015 and Apple’s Safari OSX 10.8 and iOS 8.1 have removed all support for SSLv3.
As more mailbox providers enable TLS encryption, it will protect emails in transit from eavesdropping. M3AAWG recommends starting with TLS version 1.2 for mail servers.

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May 2014: The month in email

It’s been a busy and exciting month for us here.
Laura finished a multi-year project with M3AAWG, the Messaging, Malware and Mobile Anti-Abuse Working Group (look for the results to be published later this year) and continued working with clients on interesting delivery challenges and program opportunities. Steve focused on development on the next version release of Abacus, our flagship abuse desk tool, which will also be available later this year.
And as always, we had things to say about email.
The World of Spam and Email Best Practices
We started the month with a bit of a meta-discussion on senders’ fears of being labeled spammers, and reiterated what we always say: sending mail that some people don’t want doesn’t make you evil, but it is an opportunity to revisit your email programs and see if there are opportunities to better align your goals with the needs of people on your email lists. We outlined how we’ve seen people come around to this position after hitting spamtraps. That said, sometimes it is just evil. And it’s still much the same evil it’s been for over a decade.
We also wrote a post about reputation, which is something we get asked about quite frequently. We have more resources on the topic over at the WiseWords section of our site.
Gmail, Gmail, Gmail
Our friends over at Litmus estimate Gmail market share at 12%, which seems pretty consistent with the percentage of blog posts we devote to the topic, yes? We had a discussion of Campaign Monitor’s great Gmail interview, and offered some thoughts on why we continue to encourage clients to focus on engagement and relevance in developing their email programs. We also wrote a post about how Gmail uses filters, which is important for senders to understand as they create campaigns.
SMTP and TLS
Steve wrote extensively this month about the technical aspects of delivery and message security. This “cheat sheet” on SMTP rejections is extremely useful for troubleshooting – bookmark it for the next time you’re scratching your head trying to figure out what went wrong.
He also wrote a detailed explanation of how TLS encryption works with SMTP to protect email in transit, and followed that with additional information on message security throughout the life of the message. This is a great set of posts to explore if you’re thinking about security and want to understand potential vulnerabilities.
DKIM
Steve also wrote a series of posts about working with DKIM (DomainKeys Identified Mail), the specification for signing messages to identify and claim responsibility for messages. He started with a detailed explanation of DKIM Replay Attacks, which happens when valid email is forwarded or otherwise compromised by spammers, phishers or attackers. Though the DKIM signature persists (by design) through a forward, the DKIM specification restricts an attacker’s ability to modify the message itself. Steve’s post describes how senders can optimize their systems to further restrict these attacks. Another way that attackers attempt to get around DKIM restrictions is by injecting additional headers into the message, which can hijack a legitimately signed message. If you’re concerned about these sort of attacks (and we believe you should be), it’s worth learning more about DKIM Key Rotation to help manage this. (Also of note: we have some free DKIM management tools available in the WiseTools section of our site.)
As always, we’re eager to hear from you if there are topics you’d like us to cover in June.

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