What’s the difference between a reputation issue and a technical issue?

Your open rates just fell off a cliff. Emails are going to spam, or not arriving at all. Before you can fix anything, you need to answer one question: is this a technical problem or a reputation problem? They can look identical from the outside, but the causes and the fixes are completely different.

Technical issues are about broken plumbing. Something in your configuration stopped working, and receiving servers either can't connect, can't verify your identity, or are rejecting your mail outright because authentication fails. Common culprits include broken SPF, DKIM, or DMARC records, DNS misconfigurations, expired TLS certificates, and server connectivity errors.

The hallmark of a technical issue: it hits all your mail at once, and it hits fast. One DNS change can take down delivery across every mailbox provider simultaneously. There's no gradual slide. It breaks, and then it's broken.

Reputation issues are about trust. Receiving servers and spam filters decide, based on your sending history, whether your email is worth delivering to the inbox. High complaint rates, poor engagement, spam trap hits, and blocklist entries all chip away at that trust. Reputation problems usually build gradually (unless something catastrophic triggers them, like mailing a purchased list or accidentally sending to a honey pot address).

Still the hallmark of a reputation issue: it's often mailbox-provider-specific at first. You might be fine at Google Workspace but getting junked at Outlook. Or your inbox rates are slipping slowly week over week without any obvious breakage.

How to actually tell them apart

Start with authentication headers. Send a test email to a seed address and look at the received headers. If you see SPF "fail", DKIM "neutral" or "fail", or DMARC "fail", that's a technical signal. Authentication should be passing cleanly before you investigate anything else.

Next, check your bounce codes. Hard bounces with 5xx errors mentioning authentication or DNS are technical. Bounces citing "spam policy", "reputation", "message blocked", or "low sender score" point to reputation. The bounce code is often the fastest diagnostic signal you have.

Then look at postmaster tools. Gmail Postmaster Tools and Microsoft SNDS both show you domain and IP reputation scores directly. If your authentication is passing but reputation scores are low or complaint rates are elevated, you're looking at a reputation problem, not a configuration one.

Ask yourself one more question: did this happen everywhere at once, or is it provider-specific? Technical failures tend to be universal. Reputation damage tends to be uneven, worse at one provider than others, at least to start.

When they overlap

Sometimes you have both. A misconfigured DMARC record can cause authentication failures that look like reputation damage in reports. Or a reputation issue at one provider can make their filters reject even authenticated mail. Fix the technical side first. It's faster to resolve and it eliminates a variable. If delivery improves after fixing authentication, great. If it doesn't, now you know the reputation work is still ahead of you.

Not sure where to start? Run your domain through our free blocklist checker to rule out blocklisting quickly, or check if your authentication records are parsing cleanly with the SPF checker. If you're still stuck after that, the SOS hotline is free and we'll help you read the signals.