I'm currently working for a managed service provider (MSP). We received a ticket from one of our clients who got an email from a project management company (not one of our customers), saying that people didn't receive a request they sent. The client checked their spam folder but couldn't find it, so they reached out to us for help. When I traced the email, I found that it was rejected due to DMARC verification failure: "Error: 550 5.7.509 Access denied, sending domain [the project manager's domain] does not pass DMARC verification and has a DMARC policy of reject."
I informed the client that it's entirely the sender's fault and they need to fix their DMARC and SPF configurations since we can't recover an email that was never received due to rejection at the server. However, I'm curious if there's a way to bypass DMARC checks, perhaps in Exchange or Defender, as I found mixed results. Some suggest that adding the domain to an allowlist could sometimes work, but I've heard that reliability varies and it might need a higher Defender license. It's frustrating that this large company still can't get their email system right, given how long they had to implement DMARC. Does anyone know if there's a proven method to bypass DMARC failures temporarily?
5 Answers
Honestly, I wouldn't even consider bypassing for senders who can't get their SPF and DKIM sorted. It’s the year 2026 already; they need to take responsibility for their email configuration.
Agreed. It's easy to tell them that they need to talk to their IT team because the issues are on their end.
In some configurations, you might find options to bypass DMARC, but it’s risky and usually not worth it. I’d recommend putting your foot down and insisting they address their flaws instead. There’s really no consistent workaround. Really, they just need to get their act together regarding email standards.
Yep, I’d echo that caution. Allowlists have become inconsistent at best recently. Plus, if it doesn't work, they’ll just end up blaming you.
Exactly! I’ve sent strong emails to poor configurators before; it’s essential they understand the implications.
If they can’t sort their DMARC and SPF, I’d hesitate to bypass those checks. If someone started spoofing their domain because of that, it could lead to big issues for you too. Just tell them it's 100% their responsibility to fix this.
Exactly! I won’t compromise our security. If they lose out on opportunities because they cheaped out on their IT, that's not on us.
Right? It's their issue, not mine. They need to hire someone to fix it properly.
You're right to push back on this. It's their problem; they created this issue by not adhering to email standards. All you're doing is following security protocols. They need to ensure their system is properly set up, and that’s on them to fix.
Exactly! If they can't get their email system straight, they shouldn't expect anyone else to make exceptions for them.
And if they ask for workarounds, I just say no. This is all about maintaining security.
Gmail and Yahoo also flag non-compliant emails as spam. So from their standpoint, it's definitely in their interest to fix their DMARC. If they don’t, they miss out on reaching more users, and I’ve had to redirect them to their vendor documentation to drill this point home.
Exactly! Documentation usually reinforces the need for proper setups, which can help them understand why it's vital to fix their stuff.
For sure! I make it a point to share email headers that show where the issues are coming from.
If I know the sender and they’re a good vendor, I usually explain to them that the email configuration indicates the message is spoofed and shouldn’t be delivered. I suggest they fix the setup, showing them how.