Bulk DNS records generator for cold email domains: MX, SPF, DKIM, DMARC and tracking
In short: Paste your sending domains, pick Google Workspace or Microsoft 365 and your DNS host, and get MX, SPF, DKIM, DMARC and an optional Instantly, Smartlead or lemlist tracking CNAME for every domain, as one CSV or zone-file lines. Limit: DKIM values and Microsoft's exact MX token are unique to your account; the tool marks them and says where to get them.
Every cold email sending domain needs the same set: MX records for the inbox provider, one SPF record, a DKIM key, a DMARC record and, if your tool tracks opens or clicks, a tracking CNAME. Paste the domains and the generator writes them all, with values from Google's, Microsoft's and each sending tool's own guides, and marks the DKIM values only the admin console can give.
Price: this tool is free. Checking a whole email list is from $9/mo, and the first 100 checks are free with Google, no card. See pricing
Sample result
2 sending domains on Google Workspace get 10 records: MX, SPF, DKIM, DMARC and a tracking CNAME each.
- Domains
- 2
- Provider
- Google Workspace
- Tracking
- Instantly
What this means for you
Add them at your DNS host; each domain's DKIM value comes from your own Admin console.
- MX, SPF, DKIM, DMARC per domain
- Optional tracking CNAME
- Formatted for your DNS host
- Account-specific values marked
- Bulk DNS
- Cold email
- CSV
By SimpleVerifier Team · Last updated · Runs in your browser; nothing you paste is sent to us
Also in: Português (Brasil) · Español · Deutsch · Français
How do I set up DNS for many cold email domains at once?
- Paste your sending domains, one per line. Addresses and URLs are cut down to the domain; repeats are dropped.
- Pick the inbox provider (Google Workspace or Microsoft 365) and your DNS host, so host names and values are written the way its panel or zone file wants them.
- Set the DMARC policy and, optionally, where reports go. Add a tracking CNAME for Instantly, Smartlead, lemlist or another tool if you track opens or clicks.
- Download the CSV or copy the zone files, add the records at your DNS host, then check the domains in one run with the cold email domain checker.
Example
- You enter
- Two sending domains,
getacme.exampleandtryacme.example, on Google Workspace, DMARCp=nonewith reports todmarc@acme.example, and an Instantly tracking domain. - You get
- 5 records per domain, 10 in the CSV: MX
1 smtp.google.com, SPFv=spf1 include:_spf.google.com ~all, a DKIM row atgoogle._domainkeymarked to fill from the Admin console, DMARCv=DMARC1; p=none; rua=mailto:dmarc@acme.exampleat_dmarc, and CNAMEinsttoprox.itrackly.com. - Limits
- Up to 100 domains a run; the records are built in your browser.
Which DNS records does a cold email domain need?
Four for mail, one for tracking. MX tells other servers where the domain's mail goes, so replies arrive; for Google Workspace it is smtp.google.com at priority 1 (Google), for Microsoft 365 a host ending in mail.protection.outlook.com (Microsoft). SPF lists the servers allowed to send as the domain, DKIM signs each message, and DMARC tells receivers what to do when both fail and where to send reports.
Google's sender guidelines ask every sender to set up SPF or DKIM, and senders of large volumes to set up SPF, DKIM and DMARC. A custom tracking domain is optional and only matters if your sending tool rewrites links for open or click tracking; the custom tracking domain generator explains it on its own.
Why can't the tool write the DKIM record?
Because the key is made in your account. Google generates the DKIM TXT value in the Admin console under Apps > Google Workspace > Gmail > Authenticate email (Google); Microsoft publishes two selector CNAMEs that include your tenant's own domain (Microsoft). The generator marks those rows, and the CSV leaves their value blank with a note, so nobody pastes a made-up key.
Microsoft's MX host is shown in its usual form, the domain with dots turned into dashes. Confirm it in the Microsoft 365 admin center, which lists the exact value for each domain.
What goes wrong when setting up many domains?
Two SPF records on one domain, an old MX record left in place, a DMARC record on the wrong host, and records added to one domain but not the next. One SPF record per domain is the rule (RFC 7208); if a domain already has one, merge the includes with the SPF record merger. Bulk DNS edits at some registrars replace existing records rather than adding to them, so check what each domain publishes before importing.
Then check the result, not the plan. The cold email domain checker checks MX, SPF, DKIM, DMARC, domain age and tracking for each domain, and the link under the results fills in the first ten.
Which records differ between Google Workspace and Microsoft 365?
| Record | Google Workspace | Microsoft 365 |
|---|---|---|
| MX | smtp.google.com (priority 1) | <domain-with-dashes>.mail.protection.outlook.com |
| SPF | v=spf1 include:_spf.google.com ~all | v=spf1 include:spf.protection.outlook.com -all |
| DKIM | TXT at google._domainkey, from the Admin console | CNAMEs at selector1._domainkey and selector2._domainkey, from the Defender portal |
| DMARC | TXT at _dmarc | TXT at _dmarc |
| Other | None | CNAME autodiscover to autodiscover.outlook.com |
Who uses this tool, and for what?
- Cold emailers
- Set up ten new sending domains in one sitting instead of copying records domain by domain.
- Agencies
- Hand a client's IT team one CSV with every record for every domain, formatted for their DNS host.
- Inbox resellers
- Prepare the full record set before mailboxes are created in Google Workspace or Microsoft 365.
- RevOps
- Keep a record of what each sending domain should publish, to compare against what it does.
What can’t this tool tell you?
- DKIM values and Microsoft's exact MX token are unique to your account; the tool marks them and says where to get them.
- It writes records; it doesn't read what the domains publish now. The cold email domain checker does that.
- Google Workspace and Microsoft 365 only; for Zoho, Fastmail or iCloud+, use the MX records generator one domain at a time.
- Tracking values are from each tool's help article on the date shown; if your account shows different ones, use those.
Common questions
- How many domains can I do at once?
- Up to 100 per run. Paste the rest in a second run; the CSV from each run has one row per record with the domain in the first column.
- Does it change my DNS?
- No. It writes the records in your browser; you add them at your DNS host. Nothing is sent to a server.
- Which DMARC policy should a new cold email domain use?
- Start at p=none with a report address so you can see who sends as the domain, then move to quarantine once the reports show only your own sending. The DMARC generator covers the other tags.
- Do I need a tracking domain?
- Only if your sending tool tracks opens or clicks. Without a custom one, your links go through the tool's shared domain, used by many senders. If you don't track, leave it out.
- Why is the Microsoft MX value marked?
- Because Microsoft shows the exact MX token per domain in the admin center. The usual form is the domain with dots replaced by dashes, followed by mail.protection.outlook.com; confirm it before saving.
- Can I import the zone file into Cloudflare?
- Cloudflare can import BIND zone files in its DNS settings. Rows marked as account-specific are commented out in the zone file, so add those by hand once you have the values.
Sources
Authentication and capacity are half of deliverability.
The other half is who you send to. Every hard bounce counts against the domain and inboxes you are sending from, and nothing in DNS can tell you which addresses on your list are dead.
- Bulk verification with real SMTP mailbox checks
- Hard bounces removed before a send, not discovered after
- Catch-all, disposable and role detection on every row
Plans from $9 a month, cancel anytime, no contract. Sign in with Google and your first 100 email checks are free, no card. The free tools stay free either way.