Cold Email Domain Setup: Complete Guide

Why Use Separate Domains for Cold Email?

Cold email outreach carries inherent risks to your domain reputation. If your emails get marked as spam or your domain gets blocklisted, it can affect your entire company's email deliverability - including critical communications with existing customers.

The Core Problem:

• Email providers track sender reputation at the domain level
• High bounce rates or spam complaints damage your domain score
• A damaged reputation can take months to recover
• Your main domain is too valuable to risk

The Solution: Use dedicated "sending domains" exclusively for outreach. These domains act as a buffer, protecting your main brand while allowing you to send at scale.

How Many Domains Do You Need?

The number of domains depends on your sending volume:

Daily Send Volume	Recommended Domains	Mailboxes per Domain
50-100 emails	1-2 domains	2-3 mailboxes
100-250 emails	2-4 domains	2-3 mailboxes
250-500 emails	4-6 domains	2-3 mailboxes
500-1000 emails	6-10 domains	2-3 mailboxes
1000+ emails	10+ domains	2-3 mailboxes

Golden Rule: Send no more than 50 emails per day per mailbox when fully warmed up. New mailboxes should start at 10-20 per day.

Step 1: Choose Your Domain Strategy

Option A: Similar Domains

Register domains similar to your main domain:

• If main is: company.com
• Outreach: getcompany.com, trycompany.com, companymail.com, hellocompany.com

Pros: Brand recognition, professional appearance Cons: If one is blocklisted, similar names may follow

Option B: Brand Variations

Use slight variations of your brand:

• companyteam.com, companygroup.com, companyio.com
• joincompany.com, meetcompany.com

Best Practice: Mix both strategies for diversity

What to Avoid:

• Exact match domains (can appear as spoofing)
• Random unrelated domains (looks spammy)
• Domains with hyphens or numbers
• Recently expired/dropped domains (may have bad reputation)

Step 2: Domain Registration Best Practices

Choosing a Registrar

Registrar	Best For	WHOIS Privacy	Notes
Namecheap	General use	Free	Great interface, reliable
Porkbun	Budget-conscious	Free	Lowest prices, quirky
Cloudflare	Technical users	Free	At-cost pricing
Spaceship	Cold emailers	Free	Built for outreach

Registration Checklist:

1. Enable WHOIS privacy - Always (protects your identity)
2. Register for 1+ years - Short registrations look suspicious
3. Use consistent WHOIS data - Builds trust signals
4. Avoid recently expired domains - May have existing reputation issues
5. Check domain history - Use archive.org to verify clean history

Domain Age Matters

New domains need time to build reputation:

• Week 1-2: DNS setup, basic configuration
• Week 2-4: Warmup phase (gradual sending)
• Week 4+: Production sending (start conservative)

Step 3: DNS Configuration Deep Dive

MX Records (Mail Exchange)

Point to your email provider:

Google Workspace:

Priority: 1, Value: ASPMX.L.GOOGLE.COM
Priority: 5, Value: ALT1.ASPMX.L.GOOGLE.COM
Priority: 5, Value: ALT2.ASPMX.L.GOOGLE.COM
Priority: 10, Value: ALT3.ASPMX.L.GOOGLE.COM
Priority: 10, Value: ALT4.ASPMX.L.GOOGLE.COM

Microsoft 365:

Priority: 0, Value: yourdomain-com.mail.protection.outlook.com

SPF Record (Sender Policy Framework)

Create a TXT record at @ (root):

Google Workspace:

v=spf1 include:_spf.google.com ~all

Microsoft 365:

v=spf1 include:spf.protection.outlook.com ~all

Multiple services (SendGrid + Google):

v=spf1 include:_spf.google.com include:sendgrid.net ~all

Important: Only ONE SPF record per domain. Combine all includes in a single record.

DKIM (DomainKeys Identified Mail)

1. Generate DKIM keys in your email provider admin console
2. Add the TXT record they provide
3. Enable DKIM signing for outgoing mail

Example Google Workspace DKIM:

Type: TXT
Host: google._domainkey
Value: v=DKIM1; k=rsa; p=MIIBIjANBgkqh...

DMARC (Domain-based Message Authentication)

Create a TXT record at _dmarc:

Starting Configuration (Monitoring):

v=DMARC1; p=none; rua=mailto:dmarc@yourdomain.com

After 2-4 weeks (Quarantine):

v=DMARC1; p=quarantine; rua=mailto:dmarc@yourdomain.com

Final Configuration (Reject):

v=DMARC1; p=reject; rua=mailto:dmarc@yourdomain.com

Custom Tracking Domain

If using cold email platforms, set up custom tracking:

Type: CNAME
Host: track or click
Value: provided by your email platform

This prevents emails from showing generic tracking domains in links.

Step 4: Mailbox Setup

Creating Professional Mailboxes

Use real-sounding names that match your company:

• firstname@domain.com (preferred)
• firstname.lastname@domain.com
• firstname@domain.com

Avoid:

• sales@, info@, contact@ (look automated)
• Generic names that don't exist at your company
• Multiple variations of the same person

Mailbox Configuration

1. Add profile photo - Real photo, not stock
2. Create email signature - Professional, includes contact info
3. Send personal emails first - Gmail/Outlook to mailbox
4. Reply to emails - Engagement signals
5. Subscribe to newsletters - Shows normal usage patterns

Step 5: Warmup Strategy

Manual Warmup (Week 1)

Before using any automated warmup:

1. Send 5-10 emails to friends/colleagues daily
2. Have them reply and mark as "not spam"
3. Subscribe to industry newsletters
4. Send and receive from personal accounts

Automated Warmup (Weeks 2-4+)

Use warmup tools to build reputation:

Week 2:

• 10-15 warmup emails per day
• Monitor deliverability
• Check blacklists

Week 3:

• 20-30 warmup emails per day
• Start light cold outreach (10-15 emails)
• Track open rates

Week 4:

• 30-40 warmup emails per day
• Increase cold outreach to 25-30
• Monitor bounce rates

Week 5+:

• Maintain 30-50 warmup emails
• Scale to 40-50 cold emails per day
• Continue monitoring

Never Stop Warming

Even after full production, keep warmup running:

• Maintains deliverability during low-send periods
• Offsets negative signals from cold outreach
• Keeps engagement rates high

Common Mistakes to Avoid

1. Sending Too Much Too Fast

Problem: Spikes in sending volume trigger spam filters Solution: Increase volume by max 20% per week

2. Skipping Warmup

Problem: New domains have zero reputation Solution: Always warm up for 2-4 weeks minimum

3. Using One Domain

Problem: All eggs in one basket Solution: Spread risk across 3-5+ domains

4. Poor DNS Setup

Problem: Missing authentication = spam folder Solution: Verify SPF, DKIM, DMARC are all passing

5. Generic Sending Patterns

Problem: Same time every day looks automated Solution: Randomize send times, vary volumes

6. Ignoring Bounces

Problem: High bounce rates damage reputation Solution: Verify email lists, clean immediately

7. Not Monitoring

Problem: Issues compound if not caught early Solution: Weekly deliverability audits