Overview
This guide explains how to optimize email deliverability for your domain. We handle SendGrid configuration, list management, and email infrastructure on our end. Your responsibility is ensuring proper DNS configuration and monitoring your domain's reputation.
What we handle:
✅ SendGrid setup and configuration
✅ Email list cleaning and bounce management
✅ Double opt-in and unsubscribe processing
What you need to handle:
🔧 Adding DNS records correctly
🔧 Fixing nameserver configuration issues
🔧 Monitoring domain reputation weekly
🔧 Progressing DMARC enforcement
Why Email Authentication Matters
The Security Problem
Without proper authentication, anyone can spoof emails from your domain. Here's how attacks happen:
Bad actor sends phishing email from "[email protected]" (spoofed)
Customer clicks malicious link thinking it's from you
Your domain gets blacklisted because of the attacker's actions
Your legitimate emails now go to spam
Your brand reputation is damaged
Email authentication protects:
Your brand from phishing/spoofing attacks
Your customers from malicious emails
Your domain reputation from being hijacked
Your email deliverability from degrading
Understanding the Three Pillars of Authentication
SPF (Sender Policy Framework)
Analogy: SPF is like a guest list at an exclusive event. You tell the bouncer (email provider): "Only these people (IP addresses) are authorized to say they're from my company."
What it does:
Lists which IP addresses can send email from your domain
Prevents spammers from forging emails from your domain
Checks against the "Return-Path" (hidden envelope sender)
Impact: 99.89% of successfully delivered emails have SPF properly configured.
DKIM (DomainKeys Identified Mail)
Analogy: DKIM is like a wax seal on a medieval letter. The sender seals the letter with their unique stamp, proving both authenticity and that the message hasn't been tampered with.
What it does:
Adds a digital signature to your emails (invisible to recipients)
Uses cryptographic keys to prove emails came from your domain
Verifies the email wasn't altered in transit
Impact: 99.89% of successfully delivered emails have DKIM configured.
DMARC (Domain-based Message Authentication, Reporting & Conformance)
Analogy: If SPF is the guest list and DKIM is the wax seal, then DMARC is the security policy. It tells the bouncer: "If someone's not on the guest list OR their seal is broken, here's what to do with them."
What it does:
Tells email providers what to do when SPF or DKIM fails
Provides daily reports on who's sending from your domain
Protects your domain from phishing and spoofing
Requires "alignment" - domains must match
Impact: 96.5% of successfully delivered emails have DMARC configured. 85%+ of Fortune 500 companies require it.
Your DNS Setup Checklist
Records We'll Provide
When we set up your domain, you'll receive 3 CNAME records via email:
Example format:
Record 1 (SPF/Return-Path): Type: CNAME Name: em1234.yourdomain.com Value: u1234567.wl.sendgrid.net Record 2 (DKIM Key 1): Type: CNAME Name: s1._domainkey.yourdomain.com Value: s1.domainkey.u1234567.wl.sendgrid.net Record 3 (DKIM Key 2): Type: CNAME Name: s2._domainkey.yourdomain.com Value: s2.domainkey.u1234567.wl.sendgrid.net
Adding Records to Cloudflare
Log into Cloudflare
Select your domain
Go to DNS → Records
Click "Add Record"
For each CNAME record:
Type: CNAME
Name: Copy from our email exactly
Target: Copy from our email exactly
⚠️ CRITICAL: Turn OFF the proxy (click cloud icon until gray/DNS only)
TTL: Auto
Click "Save"
⚠️ Important: The Cloudflare proxy must be OFF (gray cloud) for authentication records. This is the #1 reason authentication fails.
Adding Records to GoDaddy
Log into GoDaddy
Go to My Products → DNS
Click "Add" under Records
Select CNAME from dropdown
Add each record exactly as provided
Adding Your DMARC Record
Add ONE TXT record for DMARC monitoring:
Type: TXT Name: _dmarc Value: v=DMARC1; p=none; rua=mailto:[email protected]; pct=100
Replace [email protected] with your actual email address for receiving reports.
Start with p=none - this monitors all traffic without taking action. We'll guide you on enforcement later.
Understanding SPF in Detail
The Return-Path Domain
Every email has TWO "from" addresses:
Header From (visible): "[email protected]"
Return-Path (hidden): "[email protected]"
The Return-Path is like the return address on a physical envelope - it's where bounce messages go.
SPF checks the Return-Path domain, not the visible From address. This is why you need to authenticate the subdomain that SendGrid uses for bounces.
Adding Multiple Email Providers
If you're also sending from Google Workspace, Microsoft 365, or other services, you need to include ALL of them in one SPF record.
Examples:
SendGrid only:
v=spf1 include:sendgrid.net ~all
Google Workspace + SendGrid:
v=spf1 include:_spf.google.com include:sendgrid.net ~all
Google + Microsoft 365 + SendGrid:
v=spf1 include:_spf.google.com include:spf.protection.outlook.com include:sendgrid.net ~all
Common providers to include:
Google Workspace:
include:_spf.google.comMicrosoft 365:
include:spf.protection.outlook.comMailchimp:
include:servers.mcsv.netHubSpot:
include:_spf.hubspot.com
SPF Rules You Must Know
The "~all" ending matters:
~all= "SoftFail" - Accept but mark suspicious (recommended to start)-all= "Fail" - Reject emails not from listed sources (use after testing)+all= "Pass all" - NEVER use, defeats the purpose!
The 10 DNS Lookup Limit: Each include: statement counts as a lookup. SPF has a hard limit of 10 lookups. If you exceed this, SPF breaks entirely.
Only ONE SPF record per domain: You cannot have multiple SPF records. List all sources in one record with multiple include: statements.
DMARC Policy Progression
Phase 1: Monitoring (p=none)
Policy:
v=DMARC1; p=none; rua=mailto:[email protected]; pct=100; sp=none
When to use: When you're first setting up DMARC
What it does: Monitors ALL traffic and sends reports, but takes NO action on failures
Duration: Keep this for 2-4 weeks minimum
Why: You need to verify ALL legitimate email sources are properly authenticated before enforcing
Phase 2: Quarantine (p=quarantine)
Policy:
v=DMARC1; p=quarantine; pct=10; rua=mailto:[email protected]; sp=quarantine
When to use:
After 2-4 weeks of monitoring with p=none
When your DMARC reports show 95%+ of legitimate email is passing
You've identified and fixed all authentication issues
What it does:
Sends failed emails to spam/junk folder
pct=10means only 10% of failures are quarantined at first
Progression strategy:
Start with
pct=10(quarantine 10% of failures)After 1 week, increase to
pct=25After another week, increase to
pct=50After another week, increase to
pct=100
Why gradual? If you misconfigured something, only a small percentage of emails are affected while you fix it.
Phase 3: Reject (p=reject) - Optional
Policy:
v=DMARC1; p=reject; rua=mailto:[email protected]; pct=100; sp=reject
When to use:
After 4-8 weeks of successful quarantine mode
When DMARC reports show 99%+ pass rate
You're confident ALL legitimate sources are authenticated
You want maximum brand protection
What it does:
Completely rejects emails that fail DMARC
Failed emails never reach recipient (not even spam folder)
Strongest protection against phishing/spoofing
⚠️ WARNING: Only use p=reject when you're 100% certain all legitimate email is properly authenticated.
When NOT to Use p=reject
❌ If you have third-party services you can't fully control
❌ If you frequently add new sending services
❌ If your organization is still growing/changing rapidly
❌ If you're not monitoring DMARC reports regularly
Many successful companies stay at p=quarantine permanently - it provides strong protection without the risk of blocking legitimate email.
Real-World Example: Common Deliverability Issues
We recently diagnosed a domain experiencing deliverability problems. Here's what we found and how we fixed it.
Initial Diagnosis
Tool used: MX Toolbox Email Health Check (https://mxtoolbox.com/emailhealth/)
Results summary:
✅ Blacklist: 0 Errors (not blacklisted)
❌ Problems: 5 Errors, 4 Warnings
❌ Mail Server: 4 Errors, 2 Warnings
⚠️ DNS: 1 Error, 2 Warnings
First impression: Authentication issues and DNS configuration problems. Not blacklisted is good - this is fixable!
Issue #1: DMARC Not Enforced (CRITICAL)
Error: "DMARC Quarantine/Reject policy not enabled"
What this means:
DMARC record exists (good!)
But set to
p=none(monitoring only)Failed emails are still being delivered
The problem: Without enforcement, spoofed emails claiming to be from this domain can still reach inboxes, damaging reputation.
The fix: After confirming 95%+ pass rate, update DMARC record:
From: v=DMARC1; p=none; rua=mailto:... To: v=DMARC1; p=quarantine; pct=10; rua=mailto:...
Impact: Protects brand from spoofing, improves domain reputation.
Issue #2: No SPF Record (CRITICAL)
Error: "No SPF Record found"
What this means:
SPF record is completely missing
Email providers can't verify sending authorization
Emails showing "via SendGrid" warnings or going to spam
The fix: Add SPF record immediately:
Type: TXT Name: @ (or yourdomain.com) Value: v=spf1 include:sendgrid.net include:_spf.google.com ~all
Impact: This is CRITICAL. Without SPF, deliverability suffers by 15-20%.
Issue #3: Primary Nameserver Not Listed at Parent (HIGH PRIORITY)
Error: "Primary Name Server Not Listed At Parent"
What this means:
DNS configuration shows one set of nameservers
But the parent zone (registrar) has different information
This causes DNS resolution delays and email delivery issues
The fix:
Log into your domain registrar (where you bought the domain)
Verify nameservers match your DNS provider
Update if they don't match
Example: If using Cloudflare, nameservers should be:
ns1.cloudflare.com ns2.cloudflare.com
If using Register.com, should be:
dns013.c.register.com dns207.a.register.com (etc.)
Impact: Mismatched nameservers cause intermittent DNS failures and email delivery delays.
Issue #4: Missing Nameservers Reported by Parent
Error: Nameservers listed at DNS provider don't match what's at the registrar
What this means:
DNS servers think they're using certain nameservers
But the parent zone has different information
This is a synchronization issue
The fix:
Determine which nameservers you want to use
Log into your domain registrar
Update nameserver list to match your DNS provider
Wait 24-48 hours for propagation
Impact: DNS lookups may fail intermittently, causing authentication records to not be found.
Issue #5: Reverse DNS Mismatch (LOW PRIORITY)
Error: "Reverse DNS does not match SMTP Banner"
What this means:
Mail server hostname doesn't match its reverse DNS
Usually caused by using third-party mail forwarding
The fix: This is actually OK if:
You're only RECEIVING mail through the forwarding service
You're SENDING through SendGrid (which has proper reverse DNS)
If it's a problem:
Verify MX records point to the correct mail server
Consider using a more established mail provider
Action Plan Summary
Immediate (Do Today):
✅ Add SPF Record (CRITICAL)
Expected impact: 15-20% deliverability improvement
Time to see results: 1-4 hours after DNS propagation
✅ Fix Nameserver Configuration (HIGH PRIORITY)
Expected impact: DNS becomes reliable, no intermittent failures
Time to see results: 24-48 hours
✅ Verify DMARC Record Exists
Confirm monitoring is active
Monitor for 2-4 Weeks:
⏰ Check DMARC Reports Weekly
Review aggregate reports
Look for 95%+ pass rate
Identify any unauthorized senders
⏰ Monitor Google Postmaster Tools
Watch domain reputation (aim for "High")
Track spam rate (keep under 0.1%)
After 2-4 Weeks:
⏰ Enforce DMARC Policy (If 95%+ pass rate)
Update to
p=quarantine; pct=10Gradually increase to 100% over 4 weeks
Expected Results Timeline
Week 1 (After SPF Fix)
"Via SendGrid" warnings disappear
Inbox placement improves from ~70% to ~85%
User complaints decrease
Week 2-3 (After DNS Fix)
Email delivery becomes more reliable
No more intermittent bounces
Authentication check pass rate improves to 95%+
Week 4-8 (After DMARC Enforcement)
Inbox placement improves to 90%+
Domain reputation reaches "High" in Google Postmaster
Protection from domain spoofing activated
Long-term (3+ Months)
95%+ inbox placement rate
Strong sender reputation established
Consistent email performance
Real-world impact:
15-20% more emails reaching primary inbox
30-40% reduction in spam folder placement
Near-zero spoofed emails claiming to be from your domain
Getting Off Email Blacklists
What Are Blacklists?
Email blacklists (also called blocklists or RBLs - Real-time Blackhole Lists) are databases of IP addresses and domains that have been reported for sending spam or malicious content. When your domain or IP is blacklisted, email providers may:
Block your emails entirely
Send all your emails to spam
Add warning messages to your emails
Increase scrutiny of your sending patterns
Common reasons for blacklisting:
High spam complaint rates
Sending to spam traps (old/invalid email addresses)
Compromised email account sending spam
Poor list hygiene
Sudden volume spikes
Malware or phishing content
How to Check If You're Blacklisted
Quick Check - MX Toolbox:
Enter your domain or sending IP address
Click "Blacklist Check"
Review results for any listings
What you'll see:
✅ Green = Not listed on that blacklist
❌ Red = Listed on that blacklist
You can also check individual blacklists:
Enter your domain at each blacklist's lookup tool
Most blacklists have their own checking systems
Major Email Blacklists
1. Spamhaus (Most Impactful)
Check: https://check.spamhaus.org/
Remove: https://www.spamhaus.org/lookup/
Why it matters: Spamhaus is used by most major email providers. Being listed here has severe impact.
Removal process:
Go to the Spamhaus lookup page
Enter your IP address or domain
If listed, click the listing reference
Click "Apply for Delisting"
Fill out the form explaining:
What caused the listing
What you've done to fix it
Preventive measures implemented
Wait 24-48 hours for review
Approval factors:
Problem is genuinely resolved
Not a repeat offender
Implemented proper authentication
Evidence of list cleaning
2. Barracuda Reputation Block List (BRBL)
Check: https://barracudacentral.org/lookups
Remove: https://www.barracudacentral.org/rbl/removal-request
Why it matters: Used by many corporate email systems and security appliances.
Removal process:
Enter your IP address
Enter your email address (you'll receive confirmation)
Check the "I'm not a robot" box
Click "Remove IP Address"
Check your email for confirmation link
Click the link to complete removal
Important notes:
Barracuda uses automatic delisting for most IPs
Usually delisted within 24 hours if not reoffending
Repeated listings lead to longer listing times
Focus on fixing root cause to avoid re-listing
After removal:
Monitor sending for 48 hours
Check you're not re-listed
Continue good sending practices
3. SpamCop
Why it matters: Based on user spam reports. Fast-changing list.
Removal process:
SpamCop uses automatic time-based removal
IPs are typically delisted within 24 hours if no new spam is reported
No manual removal request process
Focus on preventing new spam reports
Prevention:
Reduce spam complaint rate below 0.1%
Clean your email list
Remove unengaged subscribers
4. SORBS (Spam and Open Relay Blocking System)
Check: http://www.sorbs.net/lookup.shtml
Remove: http://www.sorbs.net/delisting/
Why it matters: Used by smaller email providers and some corporate systems.
Removal process:
Enter your IP address
Select the listing type
Pay removal fee (if applicable) or wait for automatic expiry
Some listings require donation for expedited removal
Note: SORBS has been controversial due to fees. Many organizations have stopped using it.
5. URIBL / SURBL (URL-based Blacklists)
Check: http://multirbl.valli.org/
Remove: Varies by specific list
Why it matters: Checks URLs in emails, not just sending IPs.
Common scenarios:
Your website was hacked
Malicious links in your emails
Shared hosting with spammer
Removal:
Identify which URL is blacklisted
Fix the compromised website/URL
Submit removal request to specific list
Wait for review (usually 24-72 hours)
Step-by-Step Blacklist Removal Process
Step 1: Identify the Blacklist
Run MX Toolbox blacklist check to see which lists you're on:
https://mxtoolbox.com/blacklists.aspx
Note all blacklists showing red (listed).
Step 2: Determine the Cause
Check for:
Recent spam complaint spikes in Google Postmaster
High bounce rates in your sending data
Compromised email accounts
Sudden volume increases
Content issues
Contact us to review:
Recent sending patterns
Spam complaint rates
Bounce rates
Any suspicious activity
Step 3: Fix the Root Cause
Before requesting removal, you MUST fix the issue:
✅ Clean your email list (we can help)
✅ Remove compromised accounts
✅ Implement proper authentication (SPF, DKIM, DMARC)
✅ Reduce sending volume temporarily
✅ Review and improve email content
✅ Set up double opt-in (we handle this)
Most blacklists will reject removal requests if the underlying problem isn't fixed.
Step 4: Submit Removal Requests
For each blacklist, follow their specific removal process:
Spamhaus:
Apply for delisting
Provide detailed explanation
Wait 24-48 hours
Barracuda:
Enter IP and email
Confirm via email link
Usually removed within 24 hours
SpamCop:
Wait for automatic expiry (24 hours)
No manual removal available
Others:
Find their removal page
Follow specific instructions
Be prepared to explain fixes
Step 5: Monitor for Re-listing
After removal:
Check blacklist status daily for 1 week
Monitor spam complaint rates closely
Watch bounce rates
Verify authentication is working
Contact support if re-listed
Removal Request Template
When submitting removal requests, use this format:
Subject: Removal Request for [Your IP/Domain] IP Address/Domain: [your IP or domain] Listing Date: [when you were listed] Contact Email: [your email] Issue Identified: [Brief description of what caused the listing] Actions Taken: 1. [Specific fix implemented] 2. [Specific fix implemented] 3. [Specific fix implemented] Preventive Measures: 1. [Ongoing monitoring setup] 2. [Policy changes implemented] 3. [Authentication improvements] Current Status: - SPF: Configured and passing - DKIM: Configured and passing - DMARC: Monitoring enabled - List Hygiene: Cleaned and validated - Spam Rate: [current rate, should be <0.1%] We have addressed the root cause and implemented measures to prevent future occurrences. We respectfully request removal from your blacklist. Thank you, [Your name] [Your company]
Blacklist Removal Resources
Quick Reference Links
Blacklist | Check URL | Removal URL |
Spamhaus | ||
Barracuda | ||
SpamCop | Automatic (24hr) | |
SORBS | ||
URIBL | ||
Invaluement | ||
PSBL |
Multi-Blacklist Checkers
MX Toolbox: https://mxtoolbox.com/blacklists.aspx (Checks 100+ lists)
MultiRBL: http://multirbl.valli.org/ (Checks 200+ lists)
Debouncer Blacklist Check: https://www.debounce.io/blacklistcheck/
Prevention: How to Avoid Blacklisting
1. Maintain List Hygiene (We Handle This)
✅ We automatically remove hard bounces
✅ We clean inactive subscribers regularly
✅ We implement double opt-in
✅ We never use purchased lists
2. Monitor Key Metrics
Your responsibility:
Check Google Postmaster weekly
Keep spam rate below 0.1%
Monitor domain reputation
Alert us to any drops
3. Proper Authentication (Shared Responsibility)
Our side:
SendGrid configuration
DKIM key management
Subdomain setup
Your side:
Add DNS records correctly
Fix nameserver issues
Monitor DMARC reports
4. Gradual Volume Increases
We handle:
IP warmup for new domains
Gradual volume scaling
Traffic pattern management
5. Content Best Practices
We help with:
Email template review
Spam filter testing
Subject line optimization
You can help:
Avoid spam trigger words
Don't send to purchased lists
Keep content relevant to recipients
What to Do If Blacklisted
Immediate Actions:
Don't Panic
Most blacklists are temporary
Removal is usually straightforward
Focus on fixing the issue
Contact Support
Let us know immediately
We'll help identify the cause
We can adjust sending patterns
Stop Sending (Temporarily)
Don't make it worse
Pause non-critical emails
Focus on fixing the issue
Fix Root Cause
Address authentication issues
Clean email list
Review recent changes
Submit Removal Requests
Follow each blacklist's process
Be honest about the issue
Show what you've fixed
Monitor Closely
Check daily after removal
Watch for re-listing
Continue good practices
Blacklist Response Times
Blacklist | Typical Removal Time | Notes |
Barracuda | 24 hours | Usually automatic |
SpamCop | 24 hours | Automatic expiry |
Spamhaus | 24-48 hours | Manual review |
SORBS | 24 hours - 7 days | Some require payment |
URIBL | 24-72 hours | Depends on issue severity |
PSBL | 24-48 hours | Usually automatic |
When to Escalate
Contact support immediately if:
Listed on multiple major blacklists (3+)
Re-listed after removal
Spamhaus listing (most critical)
Can't identify the cause
Removal requests denied
Business-critical emails blocked
We can help:
Investigate sending patterns
Review spam complaint data
Check for compromised accounts
Coordinate with blacklist operators
Implement additional authentication
Diagnostic Tools Reference
MX Toolbox Email Health (Primary Tool)
Use this first - it checks everything in one place:
SPF record validity
DKIM configuration
DMARC policy
Blacklist status
DNS health
What you want to see:
✅ SPF: PASS
✅ DKIM: Records found
✅ DMARC: Policy exists
✅ Blacklist: No listings
✅ DNS: No critical errors
IntoDNS (For DNS Issues)
Use when:
MX Toolbox shows DNS errors
Nameserver problems suspected
Recently changed DNS providers
Check for:
Nameserver consistency
SOA record validity
MX record configuration
Google Message Header Analyzer
Use when:
User reports a specific email didn't arrive
Need to verify authentication on actual emails
Debugging spam folder placement
How to get headers:
Gmail: Three dots → Show original
Outlook: File → Properties → Internet headers
Apple Mail: View → Message → Raw Source
Look for:
SPF: Should be PASS
DKIM: Should be PASS
DMARC: Should be PASS
Return-Path: Should align with your domain
Google Postmaster Tools (Reputation Monitoring)
Setup (one-time):
Sign in with Google account
Add your domain
Verify ownership (add TXT record)
Wait 24 hours for data
Monitor weekly:
Domain reputation (aim for "High")
Spam rate (keep below 0.1%)
Authentication pass rate (should be 100%)
Reputation levels:
High ✅ - Excellent, keep doing what you're doing
Medium ⚠️ - Warning, investigate spam complaints
Low ❌ - Problem, reduce sending or fix list quality
Bad 🚨 - Critical, emails likely blocked
Quick Troubleshooting Guide
Issue: Emails Not Arriving
Check:
MX Toolbox for blacklist status
Verify SPF/DKIM/DMARC all exist and pass
Check Google Postmaster reputation
Review recent DNS changes
Action:
If blacklisted → See "Getting Off Email Blacklists" section above
If authentication failing → Fix DNS records
If reputation low → Contact support
Issue: Domain or IP Blacklisted
Check:
Run MX Toolbox blacklist check: https://mxtoolbox.com/blacklists.aspx
Identify which blacklist(s) you're on
Check Google Postmaster for reputation drop
Action:
See detailed "Getting Off Email Blacklists" section above for:
Specific removal processes for each major blacklist
Step-by-step removal instructions
Prevention strategies
Response time expectations
Quick links:
Barracuda removal: https://www.barracudacentral.org/rbl/removal-request
Spamhaus removal: https://www.spamhaus.org/lookup/
Contact support for help with removal process
Issue: Emails Going to Spam
Check:
Google Postmaster spam rate
Verify authentication passing
Check if blacklisted
Review email content
Action:
Fix any authentication issues first
If authentication passing, contact support for content review
Issue: "Via SendGrid" Warning
Check:
Verify all 3 CNAME records added to DNS
Check Cloudflare proxy is OFF (gray cloud)
Wait 24-48 hours for DNS propagation
Action:
Contact support to verify on our end after DNS propagation
Issue: DMARC Failing (But SPF/DKIM Passing)
Check:
Verify domain alignment in email headers
Confirm CNAME records are correct
Check Return-Path domain matches From domain
Action:
Contact support to check SendGrid configuration
Verify subdomain is properly configured
Your Action Checklist
Immediate (Do Today)
Add all 3 CNAME records to your DNS
Turn OFF Cloudflare proxy for CNAMEs (critical!)
Add DMARC TXT record
Set up Google Postmaster Tools
Run MX Toolbox health check
This Week
Verify DNS propagation (re-run MX Toolbox after 24-48 hours)
Send test emails to Gmail, Outlook, Yahoo
Verify emails land in inbox (not spam)
Set up DMARC report email filter
Document your DNS setup
This Month
Review Google Postmaster every Monday
Check DMARC reports weekly
Monitor for pass rate 95%+
Plan DMARC enforcement timeline
Monthly Maintenance
Run MX Toolbox health check
Verify IntoDNS shows no issues
Check blacklist status (https://mxtoolbox.com/blacklists.aspx)
Review Google Postmaster trends
Monitor authentication pass rates
Monthly sync with support on deliverability
Document any DNS or configuration changes
Common Patterns & Issues
Pattern #1: Missing SPF Record
Happens when: Domain recently changed DNS providers
Impact: Immediate deliverability drop
Fix time: 1-4 hours after adding record
Pattern #2: Nameserver Mismatch
Happens when: Moving between DNS providers
Impact: Intermittent issues, hard to diagnose
Fix time: 24-48 hours after correcting
Pattern #3: DMARC at p=none Forever
Happens when: Set up then forgotten
Impact: No protection from spoofing
Fix: Progressive enforcement after monitoring
Pattern #4: Cloudflare Proxy Left On
Happens when: Admin doesn't turn off orange cloud
Impact: Authentication completely breaks
Fix: 1 hour after disabling proxy
Pattern #5: Sudden Blacklisting
Happens when: Spam complaint spike, compromised account, or poor list quality
Impact: Emails blocked or sent to spam by affected providers
Fix: See "Getting Off Email Blacklists" section - typically 24-48 hours after fixing root cause
Prevention: Monitor Google Postmaster weekly, keep spam rate <0.1%
Deliverability Benchmarks
Excellent Deliverability
Inbox placement: 95%+
Open rate: 20%+
Spam rate: <0.1%
Domain reputation: High
Warning Zone
Inbox placement: 85-90%
Open rate: 15-20%
Spam rate: 0.1-0.3%
Domain reputation: Medium
Problem Zone
Inbox placement: <85%
Open rate: <15%
Spam rate: >0.3%
Domain reputation: Low or Bad
Additional Resources
Official Documentation
Email Authentication Standards
Best Practices & Research
DMARC Report Analysis
Postmark DMARC Digests (Free)
Dmarcian (Paid)
Blacklist Management
MX Toolbox Blacklist Check (Checks 100+ lists)
MultiRBL Checker (Checks 200+ lists)
Need Help?
If you're experiencing deliverability issues, blacklist problems, or need assistance with DNS configuration:
Run the diagnostic tools above
Screenshot any errors from MX Toolbox
Check if you're blacklisted (https://mxtoolbox.com/blacklists.aspx)
Contact support with:
Your domain name
Description of the issue
Screenshots of diagnostic results
Any blacklist listings found
Any recent changes to DNS
We'll help you get your deliverability back on track!