Email Authentication · SPF, DKIM & DMARC done right
Authenticate your domain so cold email lands, not bounces
Unauthenticated cold email dies in spam. FirstSales checks your domain for SPF, DKIM, and DMARC, walks you through fixing whatever's missing in minutes, and then monitors it so authentication never silently breaks. It's a core reason 87% of our senders' email lands in the primary inbox.
- Instant SPF, DKIM, and DMARC check on every connected domain
- Guided, copy-paste DNS fixes, no IT ticket and no guesswork
- Continuous monitoring with alerts the moment auth breaks
- Aligned authentication that helps drive 87% primary-inbox placement
$1 for 3 days · Cancel anytime · No DNS expertise required
The Three Records That Decide Everything
If SPF, DKIM, and DMARC aren't right, your email never reaches a human
Gmail, Outlook, and Yahoo now require authenticated email from anyone sending at volume. Get one of these three records wrong and your perfectly written cold email gets filtered before a prospect ever sees it. Here's what each record actually does, and why all three have to line up.
SPF: Proves Your Server Is Allowed to Send
SPF (Sender Policy Framework) is a DNS record that lists which servers may send email for your domain. Miss it, point it at the wrong host, or exceed the 10-lookup limit, and inbox providers treat your mail as suspicious. FirstSales reads your SPF record, flags the exact problem, and hands you the corrected line to paste.
DKIM: Signs Every Email So It Can't Be Faked
DKIM (DomainKeys Identified Mail) adds a cryptographic signature that proves your message wasn't altered and really came from you. A missing or misconfigured DKIM key is one of the fastest ways into the spam folder. We generate the key, give you the exact DNS entry, and confirm it's signing before you send.
DMARC: Ties It Together and Protects Your Domain
DMARC tells inbox providers what to do when SPF or DKIM fails, and it stops spammers from spoofing your domain. Without it, your cold email looks unverified and your brand is open to impersonation. FirstSales sets up DMARC, keeps SPF and DKIM aligned underneath it, and turns three confusing records into one quiet, monitored system.
From Unauthenticated to Inbox-Ready
SPF, DKIM, and DMARC fixed in minutes
No DNS deep-dive, no support ticket, no waiting on IT. Connect your domain, let FirstSales check and guide the fixes, and then forget about it, because we keep watching so authentication never quietly breaks.
Connect your sending domain
Add your domain or connect Gmail, Outlook, or any provider. FirstSales reads your live DNS the moment you connect, so you see your real authentication status before you send a single email.
Works with any provider Gmail, Outlook, Google Workspace, or your own SMTP.
Reads your live DNS We pull your actual SPF, DKIM, and DMARC records instantly.
No access to your DNS needed We only read records; you stay in control of your registrar.
It checks and guides every fix
FirstSales scores each record, tells you in plain language what's wrong, and gives you the exact, copy-paste DNS values to add. No syntax to memorize and no guessing whether you got it right.
Plain-English diagnosis Each record marked pass, warning, or fail with the reason why.
Copy-paste DNS values The exact host and value to add at your registrar, generated for you.
Re-checks until it's green Verify with one click after you save your DNS changes.
It monitors authentication forever
DNS changes, providers rotate keys, and records drift. FirstSales keeps checking SPF, DKIM, and DMARC continuously and alerts you the moment something breaks, so authentication never fails silently while you keep sending.
Continuous re-checks Your records are validated on an ongoing schedule, not just once.
Instant break alerts Get notified the moment SPF, DKIM, or DMARC stops passing.
Alignment kept intact We watch that SPF and DKIM stay aligned under your DMARC policy.
Proof, Not Promises
Senders who stopped fighting DNS and started landing
Teams use FirstSales to get authentication right once and keep it right, so their cold email reaches the inbox instead of dying in spam.
If you are looking to fix your sales pipeline, you should definitely try. @iuditg is the OG in cold emailing, and the product they have built- is futuristic and screams a deep understanding of email marketing. + My open rate has increased drastically, + The UI and UX are easy to understand, even for a beginner like me.
HOW AUTHENTICATION WORKS
Guided setup. Continuous monitoring. Aligned every time.
Most tools assume you already know SPF, DKIM, and DMARC and leave you to it. FirstSales checks your domain, walks you through every fix, and then watches authentication for you so it never silently breaks.
Guided SPF, DKIM, and DMARC setup
Connect a domain and FirstSales reads its DNS, scores each record, and hands you the exact values to fix what's missing. No copying syntax from forum posts and no wondering whether you got it right.
All three records, one screen SPF, DKIM, and DMARC checked and explained side by side.
Exact values, ready to paste We generate the host and value for your registrar.
One-click verification Re-check after saving and watch each record turn green.
Continuous authentication monitoring and alerts
Authentication breaks quietly. A registrar change, a rotated key, or a typo can knock you back into spam without warning. FirstSales re-checks your records continuously and alerts you the instant one stops passing.
Ongoing re-checks Your records are validated on a schedule, not just at setup.
Alerts the moment it breaks Know about an auth failure before your deliverability tanks.
Per-domain status at a glance See every connected domain's health in one dashboard.
Alignment that protects your deliverability
Inbox providers don't just want the records to exist, they want SPF and DKIM aligned with your sending domain under DMARC. FirstSales keeps that alignment intact, so your cold email reads as fully verified.
DMARC alignment maintained SPF and DKIM kept aligned to your sending domain.
Feeds 87% inbox placement Aligned auth is a core part of how we keep mail out of spam.
Protects your domain from spoofing A proper DMARC policy stops others impersonating your brand.
DNS guesswork vs guided authentication
Doing it by hand vs letting FirstSales handle it
Same goal, an authenticated domain that lands in the inbox, reached two very different ways. Here's what changes when authentication is checked, guided, and monitored for you instead of pieced together from forum posts.
- Cryptic records and syntax
- You copy SPF and DKIM strings from forum posts and hope they're correct.
- No idea if it's actually working
- Records look fine in DNS but you can't tell if mail is really authenticated.
- DMARC left off entirely
- The record that ties it together is the one most senders skip.
- Breaks silently after setup
- A registrar change or rotated key knocks you into spam with no warning.
- SPF and DKIM out of alignment
- Records exist but don't align under DMARC, so providers stay suspicious.
- Open to spoofing
- Without a DMARC policy, anyone can send email pretending to be your domain.
- Plain-English checks
- Each record marked pass, warning, or fail with the exact reason why.
- Copy-paste fixes that work
- The precise host and value to add, generated and verified for you.
- DMARC set up properly
- The policy is configured and kept aligned with SPF and DKIM underneath.
- Continuous monitoring
- We keep re-checking and alert you the instant authentication breaks.
- Alignment kept intact
- SPF and DKIM stay aligned to your sending domain under DMARC.
- Your domain protected
- A proper DMARC policy stops spammers spoofing your brand.
Guided authentication vs leaving it to you
FirstSales vs tools that leave auth to you
Most cold-email tools assume your domain is already authenticated and leave SPF, DKIM, and DMARC entirely on your plate. Authentication is where deliverability lives or dies. Here's how the jobs actually compare.
| What authentication should cover | FirstSales | Other tools |
|---|---|---|
| Checks SPF, DKIM, and DMARC for you | Included | You check |
| Plain-English diagnosis of each record | Included | Raw DNS |
| Copy-paste fixes generated for you | Included | DIY syntax |
| DMARC set up and kept aligned | Included | On you |
| Continuous monitoring with alerts | Included | One-time |
| Authentication's role in inbox placement | 87% average | 60-70% average |
| Entry price | $29/mo | $94-358/mo |
| Setup time | Minutes | Hours of DNS |
Authenticate your domain for $1
Check SPF, DKIM, and DMARC, fix what's missing in minutes, and let FirstSales monitor it so your cold email lands in the inbox, not spam.
Start your $1 trial$1 for 3 days · Cancel anytime · 87% inbox placement
FAQs
Everything about SPF, DKIM & DMARC
Can't find what you're looking for? Contact our customer support team
General
Deliverability
Can't find what you're looking for? Contact our customer support team