Blog
Top DMARC Platforms for MSPs: Features, Multi-Tenancy, and Commission Structures
October 26, 2026For an MSP, a DMARC platform needs to do more than parse aggregate reports. It should make it easy to separate client environments, control access, monitor many domains from one place, and turn DMARC management into a scalable service rather than another source of administrative overhead.
# DMARC
What the eMudhra CA compromise means for MTA-STS
October 23, 2026Eight eMudhra intermediate CA keys could be recovered because of flawed key generation. Browser vendors moved quickly to block the affected certificates. Mail software needs its own fixes, and publishing an MTA-STS policy cannot compensate for a sender that still accepts a compromised issuer.
# Email Security & Threats
DMARC Monitoring for MSPs: A Complete Guide
October 22, 2026Implementing DMARC is recommended for any domain regardless of whether or not it is sending emails. For high-volume senders, publishing a DMARC record is required by mailbox providers' rules.
# DMARC
Free SPF Checkers Compared: What They Get Wrong About Five Real-World SPF Records
October 23, 2026An SPF checker has one job: tell you what a receiving mail server will make of your record. Most free checkers get the easy cases right. A record that is missing, or one that is obviously over the 10-lookup limit, will light up red almost everywhere.
# SPF & DKIM
We Ran the Same DMARC Reports Through 11 Free XML Converters. Most Got the Math Right. Few Got the Story Right.
October 20, 2026If you publish a DMARC record with an rua= tag, you know the routine. Every morning, a pile of .gz attachments arrives from Google, Microsoft, Yahoo, and the rest. Inside each one is an XML file that says who sent mail as your domain and whether it passed. A free "DMARC XML to human" converter promises to turn that file into something you can read in a minute.
# DMARC
DKIM2: What the New Email Signature Standard Really Changes (and What It Exposes)
October 15, 2026A security gateway adds a warning banner. A mailing list changes the subject line. A forwarder sends a message to a different address. These are ordinary parts of email delivery, yet they can break authentication or make legitimate traffic difficult to distinguish from abuse.
# SPF & DKIM
Yahoo 550 5.7.9 and 554 5.7.9: Fix Authentication Bounces
October 14, 2026A Yahoo bounce can say the sender is unauthenticated or explicitly refer to the sending domain's DMARC policy. Those messages point to different checks, even when the numeric codes look similar.
# DMARC
SPF Too Many DNS Lookups: How to Fix the 10-Lookup Limit
October 7, 2026An SPF record can look perfectly valid and still fail authentication. One of the most common reasons is exceeding the SPF DNS lookup limit.
# DMARC
I Tested an LLM on Our DMARC Data. Here’s What I Found
October 1, 2026I connected Claude to the DMARKOFF MCP server and pointed it at one of our own domains: a newsletter subdomain sending through Amazon SES, 22,991 messages in the two weeks to 9 September, 53 distinct sending sources, p=none. I know every source on that domain, which makes it a fair test. I can check each conclusion the model reaches against what is actually happening
# DMARC
550 5.7.515 in Outlook: Why Email Bounces When DMARC Passes
September 30, 2026Your bounce reports SPF=Pass and DMARC=Pass. Outlook still refuses the message with 550 5.7.515. If the same diagnostic shows DKIM=Fail, those results are not contradictory.
# DMARC