An Important Issue for Email Verification

Teams usually ask which tool to use. The more important question is when to verify.

Verify at the door

An address typed into a form is at its most fixable right then. A real-time check can ask the visitor to correct "gmial.com" before the address ever reaches your database.

Verify before large sends

Addresses decay. People change jobs, mailboxes are closed and domains expire. A list that was clean six months ago can already contain a noticeable share of dead addresses. Check before any large campaign.

Verify imported lists immediately

Event lists, partner exports and old CRM files are the usual source of bad data. Verify them before they are merged with your active audience, never after.

Keep a record

Store the verification result and date with each contact. It lets you skip addresses checked recently and re-check only the ones that are due.

A simple routine

• Real-time check on every sign-up form
• Bulk check on every imported file
• Re-check inactive contacts every few months and before big campaigns

What "verify at the door" looks like

A sign-up form is the cheapest place to stop a bad address, because the person is still there. A good flow does three things:

• Checks the address while the person types or on submit, and shows a friendly message for typos ("Did you mean gmail.com?").
• Blocks disposable providers if your product needs a real mailbox, and says so in plain words.
• Never blocks on a timeout. If the check is slow or unknown, accept the address and mark it for a later check.

Before large sends

The longer a list sits, the more addresses go stale: people change jobs, mailboxes are closed, domains expire. A reasonable habit is to re-verify any list that has not been mailed in the last three months before a large campaign. For lists you mail weekly, a monthly check is usually enough.

Imports are the riskiest moment

A purchased or partner list, or a spreadsheet exported from an old tool, has no history with you. Verify it before it enters your sending platform, and keep it separate until the results are in. A single import with a high bounce rate can undo months of careful sending.

What to record

Keep the date of the last verification and the result per contact. It lets you skip addresses that were checked recently and gives you evidence of good practice if a provider or regulator asks.