Protecting users from look-alike accounts

Gmail recently started accepting mail (and calendar invitations) with non-Latin characters. A lot of fraudulent emails use non-Latin characters as a way to fool users. Google is on top of these security issues, however, and is now throwing away some mail with non-Latin characters.

the Unicode community has identified suspicious combinations of letters that could be misleading, and Gmail will now begin rejecting email with such combinations. We’re using an open standard—the Unicode Consortium’s “Highly Restricted” specification—which we believe strikes a healthy balance between legitimate uses of these new domains and those likely to be abused.

The “Highly Restricted” specification says

  • All characters in each identifier must be from a single script, or from the combinations:
    • Latin + Han + Hiragana + Katakana;
    • Latin + Han + Bopomofo; or
    • Latin + Han + Hangul
  • No characters in the identifier can be outside of the Identifier Profile

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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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June 2014: The month in email

Each month, we like to focus on a core email feature or function and present an overview for people looking to learn more. This month, we addressed authentication with SPF.
We also talked about feedback mechanisms, and the importance for senders to participate in FBL processes.
In our ongoing discussions about spam filters, we took a look at the state of our own inboxes and lamented the challenge spam we get from Spamarrest. We also pointed out a post from Cloudmark where they reiterate much of what we’ve been saying about filters: there’s no secret sauce, just a continuing series of efforts to make sure recipients get only the mail they want and expect to receive. We also looked at a grey area in the realm of wanted and expected mail: role accounts (such as “marketing@companyname.com”) and how ESPs handle them.
As always, getting into the Gmail inbox is a big priority for our clients and other senders. We talked a bit about this here, and a bit more about the ever-changing world of filters here.
On the subject of list management, we wrote about the state of affiliate mailers and the heightened delivery challenges they face getting in the inbox. We got our usual quota of spam, and a call from a marketer who had purchased our names on a list. You can imagine how effective that was for them.
And in a not-at-all-surprising development, spammers have started to employ DMARC workarounds. We highlighted some of the Yahoo-specific issues in a post that raises more questions.
We also saw some things we quite liked in June. In the Best Practices Hall of Fame, we gave props to this privacy policy change notification and to our bank’s ATM receipts.
We also reviewed some interesting new and updated technology in the commercial MTA space, and were happy to share those findings.

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Thoughts on Gmail and the inbox

Over the last few months more and more marketers are finding their primary delivery challenge is the Gmail inbox. I’ve been thinking about why Gmail might be such a challenge for marketers. Certainly I have gotten a lot of calls from people struggling to figure out how to get into the Gmail inbox. I’ve also seen aggressive domain based filtering from Gmail, where any mention of a particular domain results in mail going to the bulk folder.
It’s one of those things that’s a challenge, because in most of these cases there isn’t one cause for bulk foldering. Instead there’s a whole host of things that are individually very small but taken together convince Gmail that the mail doesn’t need to be in the inbox.
A pattern that I’m starting to see is that Gmail is taking a more holistic look at all the mail from a sender. If the mail is connected to an organization, all that mail is measured as part of their delivery decision making. This is hurting some ESPs and bulk senders. I’ve had multiple ESPs contact me in the last 6 months looking for help because all their customer emails are going to bulk folder.
Gmail’s filtering is extremely aggressive. From my perspective it always has been. I did get an invite for a Gmail account way back in the day. I moved a couple mailing lists over to that account to test it with some volume and discussion lists. I gave up not long after because no matter what I did I couldn’t get gmail to put all the mail from that list into the tag I had set up for it. Inevitably some mail from some certain people would end up in my spam folder.
Gmail has gotten better, now they will let you override their filters but give you a big warning that the message would have been delivered to spam otherwise.
Gmail_NotSpam
What are mailers to do? Right now I don’t have a good answer. Sending mail people want is still good advice for individual senders. But I am not sure what can be done about this ESP wide filtering that I’m starting to see. It’s possible Gmail is monitoring all the mail from a particular sender or ESP and applying a “source network” score. Networks letting customers send mail Gmail doesn’t like (such as affiliate mail or payday mail, things they mentioned specifically at M3AAWG) are having all their customers affected.
I suspect this means that ESPs seeing problems across their customer base are going to have to work harder to police their customers and remove problematic mail streams completely. Hopefully, ESPs that can get on the Gmail FBL can identify the problem customers faster before those customers tank mail for all their senders.

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