Here's a question that confuses most cold email teams: "If I'm only sending cold emails (not receiving), do I need MX records?"
The answer is: Yes, and here's why.
Email providers check MX records as a legitimacy signal. If your domain has no MX record, Gmail assumes you don't have a mail server. That looks suspicious. Cold email from a domain with no mail infrastructure gets filtered more aggressively.
At imisofts, we configure MX records on all client domains, even outbound-only ones. This single change improves inbox placement by 8-12%.
Let me explain the technical side, then the practical setup.
What Is an MX Record?
MX stands for "Mail eXchange." It's a DNS record that tells the world: "If you want to send email to this domain, send it to THIS mail server."
Example:
- Domain: clientacquisition.io
- MX Record: mail.clientacquisition.io
- Meaning: To email someone@clientacquisition.io, send to mail.clientacquisition.io
MX records have priority values. Lower priority = higher priority.
`
clientacquisition.io MX 10 mail.clientacquisition.io
clientacquisition.io MX 20 mail2.clientacquisition.io
`
This setup means:
- Try mail.clientacquisition.io first (priority 10)
- If that fails, try mail2.clientacquisition.io (priority 20)
Why Email Providers Check MX Records
When Gmail receives an email claiming to be from "yourname@clientacquisition.io", it checks:
- "Does clientacquisition.io have an MX record?"
- "Is that MX record pointing to a real mail server?"
- "Does that mail server accept incoming mail?"
If any of these fail, Gmail gets suspicious:
Scenario 1: No MX Record
- Domain: clientacquisition.io
- MX record: (none)
- Gmail thinks: "This domain has no mail infrastructure. Why are emails coming from here?"
- Result: Stricter filtering, higher spam folder placement
Scenario 2: Valid MX Record
- Domain: clientacquisition.io
- MX record: mail.clientacquisition.io
- Gmail thinks: "This domain has legitimate mail infrastructure. This looks real."
- Result: More lenient filtering, better inbox placement
This is reputation math. Domains with legitimate mail infrastructure look more trustworthy.
MX Records for Outbound-Only Domains
Here's where cold email teams get confused: "I'm only sending from this domain. I don't receive emails. Do I need MX records?"
Short answer: Yes, add them anyway.
Why: Email providers use MX record presence as a legitimacy signal. It costs nothing to add and improves deliverability by 8-12%.
How: Add an MX record pointing to any mail server. It doesn't have to be operational for inbound email. The presence of the record signals legitimacy.
The imisofts MX Configuration
For clients using imisofts private server infrastructure, here's the standard setup:
For Sending Domains
Option 1: No Inbound Email (Most Common)
`
clientacquisition.io MX 10 mail.imisofts.com
`
This MX record points to imisofts mail infrastructure. If someone replies to your cold email, it goes to mail.imisofts.com. You can set up email forwarding or monitoring there.
Option 2: Your Own Mail Server
`
clientacquisition.io MX 10 mail.clientacquisition.io
`
If you're running your own mail server, point to your server.
Option 3: Google Workspace Backup
`
clientacquisition.io MX 10 aspmx.l.google.com
clientacquisition.io MX 20 alt1.aspmx.l.google.com
clientacquisition.io MX 30 alt2.aspmx.l.google.com
`
This sets up Google as your inbound mail receiver (for handling replies). Your emails still send from imisofts infrastructure.
We recommend Option 1 for most cold email teams. It's simple, works, and improves deliverability.
Complete DNS Configuration for Cold Email
A properly configured cold email domain needs these records:
1. A Record (Points domain to IP)
`
clientacquisition.io A 192.0.2.100
`
2. MX Record (Mail server)
`
clientacquisition.io MX 10 mail.imisofts.com
`
3. SPF Record (Sender authentication)
`
clientacquisition.io TXT "v=spf1 ip4:192.0.2.100 include:sendgrid.net ~all"
`
4. DKIM Record (Email signature)
`
default._domainkey.clientacquisition.io TXT "v=DKIM1; k=rsa; p=MIGfMA0GCS..."
`
5. DMARC Record (Policy)
`
_dmarc.clientacquisition.io TXT "v=DMARC1; p=reject; rua=mailto:dmarc@clientacquisition.io"
`
6. CNAME Record (Tracking domain - optional)
`
click.clientacquisition.io CNAME track.instantly.com
`
Each of these records serves a purpose. Missing MX is like missing one piece of a credibility puzzle.
Setting Up MX Records: Step-by-Step
Step 1: Log into Your Domain Registrar
Examples: GoDaddy, Namecheap, Route 53, Google Domains
Step 2: Find DNS/MX Settings
Usually under "DNS Management" or "Advanced Settings"
Step 3: Add MX Record
Add new record:
- Type: MX
- Name: @ (or leave blank, depending on registrar)
- Mail server: mail.imisofts.com
- Priority: 10
Save the record
Step 4: Verify MX Record Active
Use command line or online tools to verify:
`
nslookup -type=MX clientacquisition.io
`
Expected output:
`
clientacquisition.io mail exchanger = 10 mail.imisofts.com
`
If it shows immediately: Great, you're done.
If it shows old records: Wait 24-48 hours for DNS propagation.
Step 5: Update Other Platforms
If you're using the domain with Instantly, SmartLead, Apollo, or Clay, inform them of the new MX record. Most auto-detect after 24 hours.
MX Record Priority: When You Have Multiple Servers
For enterprise setups, use multiple MX records with different priorities:
High-traffic configuration:
`
clientacquisition.io MX 5 mail1.imisofts.com
clientacquisition.io MX 10 mail2.imisofts.com
clientacquisition.io MX 15 mail3.imisofts.com
`
This means:
- Try mail1 first (priority 5)
- If mail1 is down, try mail2 (priority 10)
- If both down, try mail3 (priority 15)
For most cold email teams, one MX record is sufficient. Don't over-complicate it.
Common MX Record Mistakes
Mistake 1: Pointing to Non-Existent Server
`
clientacquisition.io MX 10 mail.fake-server.com
`
If mail.fake-server.com doesn't exist, email providers flag this as suspicious. Always point to a real server.
Mistake 2: Wrong Priority Numbers
`
clientacquisition.io MX 100 mail1.imisofts.com
clientacquisition.io MX 10 mail2.imisofts.com
`
Mail2 will be tried first (lower number = higher priority). Make sure this is intentional.
Mistake 3: Using Subdomain Without Parent MX
`
subdomain.clientacquisition.io MX 10 mail.imisofts.com
`
If you're sending from subdomain.clientacquisition.io, also add MX to parent domain:
`
clientacquisition.io MX 10 mail.imisofts.com
`
Mistake 4: Forgetting MX After Adding A Record
Domains need both A record (IP address) AND MX record (mail server). Don't skip MX.
Mistake 5: Not Verifying After Setup
Add MX record, assume it's working. Actually verify with nslookup or your registrar's tool.
MX Record Impact on Deliverability
Based on 847 imisofts client campaigns:
Domains WITHOUT MX record:
- Inbox placement: 72%
- Bounce rate: 4.1%
- Spam folder placement: 28%
Domains WITH MX record:
- Inbox placement: 84%
- Bounce rate: 2.8%
- Spam folder placement: 16%
Improvement: +12% inbox placement, -1.3% bounce rate
That's significant. MX record presence alone improves deliverability by 12%.
When to Update MX Records
Update MX when:
- You change email service providers
- You migrate to imisofts private server infrastructure
- You add backup mail servers
- You switch from shared to dedicated infrastructure
Don't update MX when:
- You're just changing tracking domains (that's CNAME, not MX)
- You're updating SPF or DKIM (different records)
- You're warming a new domain (warmup doesn't require MX changes)
Monitoring MX Records: Health Checks
Once you've set up MX records, monitor them quarterly:
`
nslookup -type=MX clientacquisition.io
`
Verify:
- MX record points to correct server
- Mail server is responsive
- No DNS errors show up
If MX record points to wrong server, update it immediately. This affects email deliverability.
The Bottom Line: MX Records Are Non-Negotiable
Adding MX records to cold email domains is a 10-minute task that improves deliverability by 12%. It's one of the easiest wins in cold email infrastructure.
At imisofts, we configure MX records for all client domains during onboarding. It's included in setup at no extra cost.
When you sign up at https://imisofts.com/cold-email-marketing#packages, our team handles MX configuration. You just point your domain to us.
Your DNS stack (A, MX, SPF, DKIM, DMARC, CNAME) is the foundation of cold email. Get it right, and everything else scales easily.