Email Verification
The process of validating that an email address is real, properly formatted, and can receive emails.
Definition
Email verification is the process of checking whether an email address is valid and capable of receiving messages. This typically involves syntax checking, domain validation (MX record lookup), and sometimes mailbox verification. Verification helps maintain list quality by identifying invalid, fake, or risky email addresses before you send to them.
Why It Matters
Sending to invalid addresses wastes resources and damages sender reputation through bounces. Verification before sending reduces bounce rates, improves deliverability, and protects your reputation. It is especially important when importing lists or collecting emails from public forms.
How It Works
Verification services perform multiple checks: syntax validation (is the format correct?), domain check (does the domain exist and accept email?), and sometimes SMTP checks (can the mailbox receive email?). Results indicate whether addresses are valid, invalid, risky, or unknown.
Best Practices
- 1Verify new email addresses before adding them to your main list
- 2Re-verify your list periodically to catch addresses that have become invalid
- 3Use real-time verification on signup forms to catch typos
- 4Remove high-risk addresses identified during verification
Built-in Email Verification
Sequenzy automatically verifies emails to keep your list clean and your deliverability high.
Learn MoreEmail Verification Check Table
| Check | What it validates | Failure example |
|---|---|---|
| Syntax check | Address follows email format rules | name@ or name@@domain.com |
| Domain check | Domain exists and can receive mail | Nonexistent domain or no usable mail-routing records |
| Mailbox check | Specific mailbox appears reachable | Deleted or fake inbox |
| Disposable detection | Address belongs to temporary email service | One-time signup inbox |
| Role account detection | Address is shared by a group | info@, support@, or admin@ |
Verification Result Table
| Result | Meaning | Recommended action |
|---|---|---|
| Valid | Address appears deliverable | Add or keep in active list |
| Invalid | Address is not deliverable | Suppress before sending |
| Risky | Catch-all, role, disposable, or uncertain address | Segment carefully or request confirmation |
| Unknown | Verification service cannot determine status | Avoid high-volume sends until confirmed |
| Duplicate | Address already exists in the list | Merge data instead of creating a new subscriber |
Verification Timing Table
| Timing | Best for | Why |
|---|---|---|
| Real-time at signup | Public forms and lead magnets | Catches typos before they enter the list |
| Before import | CSV uploads and migrations | Prevents bulk bounce spikes |
| Before major campaign | Older or inactive lists | Protects reputation before high-volume sends |
| Periodic cleanup | Mature databases | Removes addresses that decay over time |
| Before reactivation | Dormant subscribers | Avoids re-engaging invalid or risky inboxes |