Deliverability Guide

SPF, DKIM & DMARC Setup Guide

A step-by-step technical guide to setting up email authentication — the single most important thing you can do for inbox placement.

01 Why Email Authentication Matters

Email authentication is a set of technical standards that prove to receiving mail servers (Gmail, Outlook, Yahoo) that you are who you say you are — and that your emails haven't been tampered with in transit.

Without proper authentication, even legitimate emails from reputable senders can be flagged as spam or rejected outright. Major inbox providers like Gmail and Yahoo now require SPF, DKIM, and DMARC for bulk senders — without them, your emails will not be delivered.

  • Authentication is required by Gmail and Yahoo for senders sending over 5,000 emails/day
  • Unauthenticated emails are 3x more likely to land in spam even at lower volumes
  • DMARC protects your domain from being spoofed by phishers and scammers
  • BouncePro generates all required records — you just need to add them to your DNS
BouncePro makes this easy. Go to Settings → Sending Domains → Add Domain and we generate your personalized SPF, DKIM, and DMARC records automatically. This guide explains what each record does and how to add them.

02 Setting Up SPF

📋
SPF
Sender Policy Framework

SPF is a DNS TXT record that lists which mail servers are authorized to send email on behalf of your domain. When a receiving server gets an email claiming to be from you, it checks your SPF record to verify the sending server is on your approved list.

How to add your SPF record:

Step 1 — Check if you already have an SPF record

You can only have one SPF record per domain. Check first by looking up your existing DNS TXT records. If you already have one, you need to modify it — not create a new one.

# Check existing SPF using command line:
nslookup -type=TXT yourdomain.com
# Or use an online SPF checker tool

Step 2 — Add or update your SPF record

Log into your domain registrar (GoDaddy, Namecheap, Cloudflare, etc.) and add a TXT record:

# New SPF record (if you don't have one):
Type: TXT
Name: @ (or leave blank)
Value: v=spf1 include:bouncepro.io ~all

# If you already send from other services (e.g. Google Workspace):
Value: v=spf1 include:_spf.google.com include:bouncepro.io ~all
~all vs -all: Use ~all (softfail) while setting up, then switch to -all (hardfail) once you've confirmed everything works. Hardfail tells servers to reject unauthorized emails outright.

Step 3 — Wait for propagation

DNS changes typically take 15 minutes to 48 hours to propagate globally. BouncePro will automatically detect when your SPF record is live.

03 Setting Up DKIM

🔑
DKIM
DomainKeys Identified Mail

DKIM adds a cryptographic digital signature to every email you send. The receiving server uses a public key in your DNS to verify the signature — proving the email came from you and hasn't been modified in transit.

How to add your DKIM record:

Step 1 — Get your DKIM record from BouncePro

Go to Settings → Sending Domains in your BouncePro account. After adding your domain, BouncePro will generate a unique DKIM CNAME record for you.

Step 2 — Add the CNAME record to your DNS

# Your DKIM record will look like this:
Type: CNAME
Name: bouncepro._domainkey.yourdomain.com
Value: bouncepro.dkim.bouncepro.io
Note: Some DNS providers require you to enter just the subdomain portion (e.g. bouncepro._domainkey) rather than the full record name. Check your registrar's documentation if unsure.

Step 3 — Verify in BouncePro

Return to Settings → Sending Domains and click "Verify". BouncePro will confirm your DKIM record is correctly configured.

04 Setting Up DMARC

🛡️
DMARC
Domain-based Message Authentication, Reporting & Conformance

DMARC tells receiving servers what to do with emails that fail SPF or DKIM verification. It also generates reports showing you who is sending email using your domain — protecting you from phishing and spoofing attacks.

DMARC Policies

  • p=none — monitoring only, no action taken. Start here.
  • p=quarantine — failed emails go to spam folder. Move to this after monitoring.
  • p=reject — failed emails are rejected entirely. The most secure setting.

Step 1 — Start with a monitoring policy

Type: TXT
Name: _dmarc.yourdomain.com
Value: "v=DMARC1; p=none; rua=mailto:dmarc@yourdomain.com; ruf=mailto:dmarc@yourdomain.com; fo=1"

Step 2 — Review reports and tighten policy

After 2–4 weeks on p=none, review your DMARC reports to confirm all legitimate sending sources are passing. Then move to quarantine, and eventually reject:

# Final recommended DMARC record:
"v=DMARC1; p=reject; pct=100; rua=mailto:dmarc@yourdomain.com"
BouncePro's DMARC viewer in Settings → Sending Domains shows you a summary of your DMARC reports so you don't have to parse raw XML files.

05 Verifying Your Records

After adding your DNS records, verify them using these free tools:

  • MXToolbox (mxtoolbox.com) — check SPF, DKIM, and DMARC records
  • Mail-Tester (mail-tester.com) — send a test email and get a full deliverability score
  • Google Postmaster Tools — monitor domain reputation with Gmail specifically
  • BouncePro Domain Settings — built-in verification shows green checkmarks when all records are correct

All three records should show as valid before sending any campaigns. BouncePro will warn you if you attempt to send from an unverified domain.

06 Authentication Checklist

✓
SPF record added
TXT record at your root domain authorizing BouncePro to send on your behalf.
✓
Only one SPF record exists
Multiple SPF records cause failures — merge all sending services into one record.
✓
DKIM CNAME record added
CNAME record added from your BouncePro domain settings.
✓
DMARC record added
At minimum p=none with a reporting address to start receiving reports.
✓
All records verified in BouncePro
Green checkmarks on all three records in Settings → Sending Domains.
✓
Test email passes authentication
Send a test via mail-tester.com and confirm SPF, DKIM, and DMARC all pass.
✓
Plan to tighten DMARC policy
Schedule a review in 4 weeks to move from p=none to p=quarantine or p=reject.

Next step: Email Sender Reputation Guide →

BouncePro Generates Your Records Automatically

Add your domain and we give you the exact DNS records to copy-paste — no technical knowledge required.

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