It’s easy to tell if a domain is using SPF – look up the TXT record for the domain and see if any of them begin with “v=spf1”. If one does, they’re using SPF. If none do, they’re not. (If more than one does? They’re publishing invalid SPF.) AOL are publishing SPF. Geocities aren’t. For DKIM it’s harder, as a DKIM key isn’t published at a...
The philosophy of DMARC
We know that legitimate email sent with valid SPF and a DKIM signature often breaks in transit. SPF will fail any time mail is forwarded – via a mailing list, a forwarding service used by the recipient, or just ad-hoc forwarding. DKIM will fail any time the message is modified in transit. That can be obviously visible changes, such as a mailing list tagging a subject header or adding a...
Tools!
I just added a DMARC validation tool over on tools.wordtothewise.com. You can give it a domain – such as ebay.com – and it will fetch the DMARC record, then explain and validate it. Or you can paste the DMARC record you’re planning to publish into it, to validate it before you go live. If you’ve not seen our tools page before, take a look. As well as DMARC we have a DKIM...
Fun with opinions
Over the last few weeks I’ve seen a couple people get on mailing lists and make pronouncements about email. It’s great to have opinions and it’s great to share them. But they’re always a little bit right… and a little bit wrong. SPF is dead! This came from the new ESP of an experienced mailer. They were recommending not publishing SPF records because it was “an...
Gmail showing authentication results to endusers
A bit of older news, but worth a blog post. Early in August, Gmail announced changes to the inbox on both the web interface and the android client. They will be pushing authentication results into the interface, so end users can see which emails are authenticated. These are not deliverability changes, the presence or absence of authentication will not affect inbox delivery. And the gmail Gmail...
BT Internet
I’ve been seeing reports for the last few weeks that a lot of folks are having problems getting mail into BT Internet. Many people are reporting the response smtp;554 Message rejected for policy reasons (3.2.2.1) – Please report any problems to BT via the postmaster btinternet.com mailbox and include your sending ip address with an example header of your email Unfortunately, the...
July 2016: The Month in Email
We got to slow down — and even take a brief vacation — in July, but we still managed to do a bit of blogging here and there, which I’ll recap below in case you missed anything. At the beginning of the month, I wrote about email address harvesting from LinkedIn. As you might imagine, I’m not a fan. A permissioned relationship on social media does not equate to permission to email...
SPF ?all
The most read post on the blog is Authenticating with SPF: -all or ~all. In fact, it’s in the top 5 posts every single day. We still get comments on it, too. Usually from folks who disagree with my recommendations. I still stand by my recommendations, though. It doesn’t really matter if you choose ~all or -all in your SPF records. Why? No major provider is rejecting mail solely...
Don't just follow the HOWTO
There are so many moving parts to ensure good email deliverability. Email marketers need to know marketing, they need to know email and they need to know design. The technical bits of email can be a challenge to learn, and many folks who write tutorials and How-Tos write them for a different audience than marketers. One of the things I’m trying to do is demystify the technical end of email...
Ask Laura: Can you help me understand no auth / no entry?
Dear Laura, I’m a little confused by the term “no auth / no entry”. Gmail and other major receivers seem to be moving towards requiring authentication before they’ll even consider delivery. Does this just mean SPF and DKIM, or does this mean the much more stringent DMARC, as well? Thanks, No Shirt, No Shoes, No What Now? Shirtless & Shoeless, “No auth / no entry” is...