Proof That I’ve Been Doing This a While: A Look Back at 2015

2015: (Almost) All DMARC, All The Time

2014 and 2015 were important times for DMARC adoption and I'm glad I was able to document what was happening, when DMARC adoption was becoming kind of a big deal.

• 2015: The Year of DMARC. A roundup of key moments in DMARC adoption, as major ISPs and brands began enforcing stronger policies. 
• Use this ONE WEIRD TRICK when implementing a DMARC record. A straightforward best practice: make sure the domain in your "From" address aligns with your SPF and DKIM authentication.
• Use the SECOND WEIRD TRICK when implementing your DMARC record. Don't forget to add a ruf=tag if you want to receive forensic failure reports via DMARC.
• Mail forwarding in a DMARC world. Forwarding can break DMARC. Here's how that happens, and some of the ways to mitigate the fallout.
• DMARC and mailing lists: We survived!. A look at how mailing lists adapted to the challenges of "p=reject" by rewriting headers and updating message flow.

ISP and Domain Shutdowns in 2015

Plenty of ISPs and services retired domains or addresses that year. Wow, I've been tracking dead domains for a while, haven't I?

• French ISP Orange shutting down voila.fr. Orange announced they were shutting down the voila.fr domain, impacting millions of legacy users.
• Yahoo Mail China is no more. Yahoo ended email services in China, following a broader exit from the region.
• Verizon retiring inactive email addresses. Verizon cleaned house on dormant accounts. a good reminder to scrub old contacts from your lists.
• Domains clear.net and clearwire.net have been retired. Remember Clear, the 4G technology provider? They came, they hosted mailboxes, they left.

Security, Encryption and Blocking Updates in 2015

Security was on everyone's mind, especially Google's.

• Gmail to flag unencrypted email connections. Gmail began warning users about messages received over unencrypted connections. This pushed senders to get serious about TLS.
• Is my DKIM key insecure? Understanding false positive warnings suggesting DKIM key length problems(when that's not really the issue). But of course, longer keys are better.
• Sending mail over IPv6? Authenticate! Sending email via IPv6 doesn't mean skipping SPF, DKIM, or rDNS. Authenticate, or get filtered. (Featuring Word to the Wise!)
• Google now allows you to "block" senders in Gmail. Making it easier for users to manually keep unwanted interlopers out of the inbox.

Email Industry Developments in 2015

A lot was shifting across the broader email landscape.

• Spamhaus sued for libel in the UK. A legal challenge with potential implications for anti-abuse providers worldwide. Spamhaus survived, and reputation services survived. I am glad.
• Microsoft updates use of List-Unsubscribe header. Microsoft continued to encourage best practices by recognizing standards-based unsubscribe mechanisms.
• Gmail spam filter changes bite Linus Torvalds. Gmail mistakenly flagged the Linux kernel mailing list. Even Linus wasn't immune to false positives.

A Few Other Random Bits and Bobs from 2015

And finally, some advice from back then that mostly still holds up.

• From address: Don't use an invalid domain name. If your sending domain isn't valid or doesn't resolve, your mail might bounce or get filtered.
• Return Path: When is it OK to use a shared IP?. Sometimes shared IPs are fine, but only when reputation management is tight and partners are vetted.
• What RRVS Doesn't Fix. RRVS (Require Recipient Valid Since) is meant to help prevent mail from reaching reassigned addresses. But it has limits. and doesn't stop delivery of messages already in the pipeline or sent without join-date knowledge.

This was just one year of content, and looking back, I'm proud of how much ground we covered. and how much of it is still relevant today. Whether it's DMARC, authentication, security, or mailbox provider filtering, behavior, these are the same themes that continue to matter a decade later.

Thanks for being part of this ongoing journey. Here's to ten more years of helping folks send better (and safer) email.