Collaborate Disseminate
Interest in DMARC is growing exponentially, but most of the organizations that deploy DMARC don’t actually achieve its full anti-spoofing benefits. Here’s how to overcome the most common DMARC deployment challenges. In our conversations wit… Continue reading 7 common mistakes people make with DMARC
I always thought that to authenticate email we needed both SPF and DKIM (and DMARC). But email is confusing and recently I found myself asking why we can’t do with just SPF or DKIM. I then discovered that the problem with using just SPF is… Continue reading Do we need SPF when we have DKIM?
Our Exchange 2016 server and set up is a bit of a mess, but the short of it is that we have numerous domains configured in it, including multiple separate business divisions that probably should have their own mail server. DK… Continue reading Exchange 2016, multiple domains, correct DKIM setup? [migrated]
I set up DKIM, DMARC and SPF on my domain/server a few years ago, and never touched it again since then.
Here are my DNS records (my domain is mydomain.com and my IP addresses are 1.1.1.1 and 2001::1):
mydomain.com. 0 TXT “v=spf1… Continue reading DMARC report for mails I didn’t send
If a mail sender encodes the sender address in the from: field, the Mail Transfer Agent only checks the sender after the unencoded @. In this way, protection mechanisms like SPF/DKIM/DMARC are subverted.
Is there are any mit… Continue reading how to mitigate mailsploit
I have been playing around with sending emails via telnet using text commands.
Theoretically…
Say I send an email from a typical mail agent that adds a dkim signature from a@a.com to b@b.com.
If I grab the message sou… Continue reading Theoretical DKIM Question
S/Mime can be used to encrypt email and it can also be used by the sender to provide his digital signature so that the recipient is able to confirm the authenticity of the sender.
Why then do we still need to have DKIM impl… Continue reading Why do we need DKIM to be used along with S/Mime?
I’ve seen this question asked before, but unfortunately, don’t understand the responses. I think its something to do with “from” headers being defined differently by different standards. I’ve added all the domains in the “from” to SPF rec… Continue reading Why is DMARC failing when SPF and DKIM are passing?
Recently we have encountered 2 instances of mass phishing attempts from 2 accounts using SendGrid although the SPF is published as hard fail for both without SendGrid records and only for the mail servers authorized to send. … Continue reading SendGrid emails ignoring SPF records for mass phishing attempts
From RFC6376 #page-29, it says:
In hash step 1, the Signer/Verifier MUST hash the message body, canonicalized using the body canonicalization algorithm specified in the “c=” tag and then truncated to the length specified in the “l=” … Continue reading Does DKIM protect the whole body message?