Tagspf

Four things to check before your next mailing

Like many bits of technology, email is often set-and-forget. Everything is checked and rechecked during setup, and then no one goes back and looks at it again. But mail programs are not static, and people make changes. These changes don’t really break things, but over time they can create their own set of problems. Setting aside some time every quarter or even every year to check and make...

Office365/EOP IPv6 changes starting today

Terry Zink at Microsoft posted earlier this week that Office365/Exchange Online Protection will have a significant change this week. Office365 uses Exchange Online Protection (EOP) for spam filtering and email protection. One of the requirements to send to EOP over IPv6 is to have the email authenticated with either SPF or DKIM.  If the mail sent to Office365/EOP over IPv6 is not authenticated...

Authentication and Repudiation

Email Authentication lets you demonstrate that you sent a particular email. Email Repudiation is a claim that you didn’t send a particular email.   SPF is only for email authentication1 DKIM is only for email authentication DMARC is only for email repudiation   1 SPF was originally intended to provide repudiation, but it didn’t work reliably enough to be useful. Nobody uses...

March 2015: The month in email

Happy March! We started the month with some more movement around CASL enforcement from our spam-fighting friends to the north. We noted a $1.1 million fine levied against Compu-Finder for CASL violations, as well as a $48,000 fine to Plentyoffish Media for failing to provide unsubscribe links. We noted a few interesting things: the fines are not being imposed at the maximum limits, violations are...

Bad SPF can hurt your reputation

Can a bad SPF record ruin your delivery, even though all your mail still passes SPF? Yes, it can. One of our clients had issues with poor delivery rates to the inbox at gmail and came to us with the theory that it was due to other people using their domain to send spam to gmail. This theory was based on ReturnPath instrumentation showing mail “from” their domain coming from other IP...

Salesforce SPF and now DKIM support

Salesforce has published a SPF record for sending emails from Salesforce for years and with the Spring ’15 release, they will provide the option to sign with DKIM. The SPF record is straight forward, include:_spf.salesforce.com which includes _spf.google.com, _spfblock.salesforce.com, several IP address blocks, mx, and ends with a SoftFail ~all. Salesforce Knowledge Article Number:...

Email Authentication in a nutshell

There are 3 types of authentication currently in use for email. DKIM SPF DMARC The different strategies do different things with email. DKIM cryptographically signs emails, preventing changes in transit, and designates a “responsible domain” through the d= value in the signature. SPF compare the sending IP and the envelope from (also known as the bounce string, return path or 5321...

Office365 checking DMARC on the inbound

According to a recent blog post, Office365 is starting to evaluate incoming messages for DMARC. I talked a little bit about DMARC in April when Yahoo started publishing a p=reject message. DMARC stands for Domain-based Message Authentication, Reporting and Conformance. What DMARC does is allow domain owners to publish policy statements in DNS telling receiver domains what to do with messages that...

Spam, Phish or Malware?

Some mornings I check mail from my phone. This showed up this morning. My first thought was “oh, no, Pizza Hut is spamming, wonder who sold them my address.” Then I remembered that iOS is horrible and won’t show you anything other than the Friendly From and maybe it was some weird phishing scheme. When I got to my real mail client I checked headers, and sure enough, it...

Authenticating with SPF: -all or ~all

What is SPF? Sender policy framework (SPF, RFC 7208) is an authentication process that ties the 5321.from (also known as the mail from, envelope from or return path) to authorized sending IP addresses. This authorization is published in a TXT record in DNS. Receivers can check SPF at the beginning of a SMTP transaction, compare the 5321.from domain to the connecting IP address and determine if...

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