The one-sentence version#
Lead verification confirms that a prospect's address exists and accepts mail before it enters a sequence, using syntax checks, MX lookups, SMTP probing, and catch-all detection. Enrichment adds firmographic and role data used for personalization.
Why you should care#
Bounce rate is the fastest way to burn an outbound domain. Unverified purchased lists routinely bounce 10 to 30 percent.
The mental model#
Think of lead email verification as a contract between you and the mailbox providers receiving your mail. You publish or configure something they can check; they check it on every message; the result feeds their decision about where your message lands. Everything below is about making that check pass consistently.
Your first setup, step by step#
- Verify every address through an API before it enters a sequence.
- Segregate catch-all domains and send to them at lower volume.
- Refresh verification for any lead older than 90 days.
- Enrich with 3 to 5 data points that drive the opening line.
Words you will see#
- Mailbox provider: Gmail, Microsoft, Yahoo, Apple, and the corporate gateways that decide where mail lands.
- Authentication: proof that a message is from who it says it is (SPF, DKIM, DMARC).
- Reputation: the provider's running score of your domain and IP.
- Placement: whether a message reaches the inbox, spam, or is rejected.
Common mistakes#
- Trusting a vendor's 'verified' label from months ago.
- Treating catch-all as valid.
Frequently asked questions#
What bounce rate is safe for cold email?
Under 2 percent. Above 5 percent, pause and re-verify the list before continuing.