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B2B Email Deliverability Fixes Guide

Musa Mustafa· Published December 9, 2025

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Frequently Asked Questions

Find answers to common questions about email verification.

What are the three essential technical fixes (The Authentication Trifecta) I must implement?

The three mandatory technical fixes required by all Internet Service Providers (ISPs) are SPF (Sender Policy Framework), which specifies authorized mail servers; DKIM (DomainKeys Identified Mail), which adds a digital signature to verify integrity; and DMARC (Domain-based Message Authentication, Reporting, and Conformance), the policy that tells the receiving server what to do if an email fails the SPF or DKIM check.

Why should I use a subdomain for my B2B cold outreach instead of my main company domain?

You should use a subdomain (e.g., outreach.yourcompany.com) to isolate your sender reputation. Cold outreach carries a high risk of being flagged as spam; if the subdomain's reputation is damaged, your primary domain's reputation, used for essential client communication, remains protected and functional.

What is the maximum acceptable Hard Bounce Rate, and why is it so important?

Your maximum acceptable Hard Bounce Rate is $<2\%$. Exceeding this low threshold signals poor list hygiene and spammy practices to ISPs because a hard bounce occurs when an email address is permanently invalid, which instantly and severely degrades your sender reputation.

What is a "Spam Trap," and what should I do if I hit one?

A Spam Trap is a deceitful email address used by ISPs to identify senders with poor data quality, such as those who purchase lists. If you hit a spam trap, your sender reputation will be severely damaged, requiring immediate aggressive list cleaning and verification.

If my emails are going straight to the spam folder, what is the first step I should take?

The first step is to perform a technical and reputation check. You should check for blocklist activity using a checker tool, review your Google Postmaster Tools dashboard for immediate drops in your reputation, and then audit your email content for excessive spam trigger words, large images, or aggressive promotional language.

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