Deliverability Hub
The Deliverability Hub gathers on one page everything that decides whether your emails land in the inbox: your domain’s authentication, the quality of your recipient list, your sender reputation and the message itself. Open it from the Deliverability group of the sidebar.
Whether a message reaches the inbox is decided by the recipient’s mailbox provider, exactly as for an email you write by hand. The hub does not change that; it shows you what the provider sees and fixes what can be fixed on your side. Background: Deliverability: landing in the inbox.
Authentication
Section titled “Authentication”Click Check my domain to run the email reputation checker on your own address. The card shows the five records that matter most:
| Row | What it means |
|---|---|
| MX records | Your domain can receive email. A domain without MX records is a red flag for providers. |
| SPF protection | Which servers may send for your domain. Google Workspace needs include:_spf.google.com. |
| DKIM signature | Your outgoing mail is signed. Set it up in the Google Admin console under Gmail → Authenticate email. |
| DMARC policy | What providers should do with unauthenticated mail claiming to be you. p=none passes with a warning; quarantine or reject passes. |
| Blocklists | Your domain and its mail servers are not listed on Spamhaus, SpamCop or Barracuda. |
A free @gmail.com address is authenticated by Google already. For a custom domain, SPF, DKIM and DMARC are set in your domain’s DNS, not in Mail Merge; Gmail and Yahoo require all three for bulk senders. The checker is limited to 20 runs per day; Open the full checker shows the complete scored report, including the domain’s age and BIMI.
Email verification
Section titled “Email verification”Sending to addresses that bounce is one of the strongest spam signals there is. Verification checks every recipient before the campaign leaves, without sending anything to them, and sorts the list into three verdicts:
| Verdict | Meaning | Examples |
|---|---|---|
| Valid | Nothing wrong was found. | |
| Risky | Deliverable, but worth a look. | A role address (info@, support@, noreply@), or a domain that is on a spam blocklist. |
| Invalid | The email will not arrive. | A typo (john@gmailcom), a disposable address (mailinator.com), a domain with no mail server, or an address that bounced in one of your earlier campaigns. |
Mail Merge runs its own checks (syntax, disposable domains, your bounce history, mail-server records, the Spamhaus domain blocklist). It does not probe the recipient’s mail server, so an unknown mailbox at a working domain can still bounce; the verdict catches the typos and dead domains that make up most bounces.
Verify a list
Section titled “Verify a list”- In the campaign builder, choose your recipients and your template, then open the Review step.
- Click Verify recipients. Large lists are checked in batches; a few hundred addresses take a few seconds.
- The summary line reads, for example, 48 valid · 3 risky · 2 invalid, with the breakdown underneath, problems first.
- Skip invalid addresses is switched on automatically when anything is invalid. Leave it on: those rows are marked Skipped in your sheet with a note, and the email is never sent to them. Untick it to send anyway.
Verdicts are remembered for 30 days on your contacts, so re-verifying the same list is instant and does not count against the limit of 5,000 fresh verifications per day. Unsubscribed and blocked contacts are reported as such; they are excluded from every send regardless.
The hub’s Email verification card shows the result of your last run. AI agents get the same check through the verify_recipients tool, and send_campaign accepts skipInvalidRecipients to drop the invalid ones.
Warm-up
Section titled “Warm-up”The Email warm-up card shows whether warm-up is running, paused or not enabled, and your current reputation score. It is the same information as the warm-up page, where you start, pause and tune it. Warm-up is a Professional feature; start it a week or two before a large campaign from a new or quiet address.
Pre-send checks
Section titled “Pre-send checks”Every campaign is audited in the Review step before it leaves. The Pre-send checks card lists what the audit looks for: a missing unsubscribe link, an empty subject, a subject in ALL CAPS or longer than inboxes display, wording that spam filters flag, repeated !!! or ???, and an image-only message with no text. These are warnings, never a block; fix what you can and send yourself a test.
| Free | Personal | Professional | |
|---|---|---|---|
| Authentication check | ✓ | ✓ | ✓ |
| Pre-send checks | ✓ | ✓ | ✓ |
| Email verification | ✓ | ||
| Email warm-up | ✓ |
Free and Personal accounts see the whole page; the verification and warm-up cards show an upgrade prompt. See Pricing.