Email Deliverability Starts With Data Quality

Every outbound team with deliverability problems goes through the same checklist. Check SPF, DKIM, DMARC. Check the warm-up. Check the sending volume. Check the content for spam triggers. Rotate domains. Adjust send times.

These are all important. But they are not the root cause for most teams. The root cause is data quality.

The Direct Connection

When you send an email to an invalid address, it bounces. When your bounce rate exceeds 3-5%, email service providers start penalizing your sending domain. When your domain is penalized, even your emails to valid addresses start landing in spam.

This is not a theoretical risk. It is the most common cause of deliverability problems in cold outbound. Teams buy a list with 15-20% invalid emails, send a campaign, see bounce rates spike, watch their deliverability crater, and then spend weeks trying to fix it with technical adjustments that do not address the underlying problem.

The fix is not better infrastructure. The fix is better data.

What "Verified Email" Actually Means

There are three levels of email verification:

Syntax check. Confirms the email address is formatted correctly. This catches obvious typos but nothing else. Every data provider does this. It is table stakes.

Domain check. Confirms the domain exists and has active MX records. This catches emails at companies that have shut down or changed domains. Most data providers do this.

SMTP verification. Connects to the mail server and confirms the specific mailbox exists and accepts mail. This catches the emails that syntax and domain checks miss: the ones where the domain is valid but the person no longer works there. This is the verification that matters.

VerifiedByTed performs SMTP-level verification on every email address. We also flag catch-all domains, which are domains configured to accept mail for any address, making individual verification impossible. You know exactly which emails are confirmed valid and which are uncertain.

Beyond Email: Company and Contact Verification

Email deliverability is the floor, not the ceiling. Even a valid email address is wasted if the contact is not the right person or the company does not match your ICP.

A "verified lead" should mean:

• The email address accepts mail (SMTP verified)
• The contact currently holds the listed title at the listed company
• The company is active, operating, and matches your size/revenue criteria
• The data was verified recently, not months ago

If any of these are missing, you are building campaigns on incomplete data. And incomplete data leads to wasted effort, even if deliverability is fine.

The Numbers

Teams that switch from unverified lists to SMTP-verified leads typically see:

• Bounce rates drop from 10-15% to under 3%
• Deliverability rates increase from 70-80% to 95%+
• Reply rates increase 40-80% (because more emails are reaching real inboxes)
• Domain health scores improve within 2-4 weeks

The investment in better data pays for itself in the first campaign.