MX Records Explained: Setup for Cold Email

MX records tell the internet where to deliver email for your domain. Here's how to configure them correctly.

What is an MX record?

An MX (Mail Exchange) record is a DNS record that tells the internet which mail server should receive email sent to addresses at your domain. When someone sends an email to you@yourdomain.com, their mail server looks up your domain's MX records to find out where to deliver the message.

MX records are different from SPF records (which specify who can send from your domain) and different from DKIM/DMARC (which handle authentication and policy). MX records handle incoming mail. If your MX records are wrong or missing, you won't receive any email.

  • MX records only affect incoming email — they don't directly affect your ability to send.
  • You can have multiple MX records with different priorities for redundancy.
  • Changes to MX records can take up to 48 hours to propagate globally.

MX record structure

An MX record has three components: the record name (usually @ or your domain name), the priority (a number — lower numbers are tried first), and the mail server hostname (the server that should receive your mail). Multiple MX records create a priority list — if the first server is unavailable, the sending server tries the next one.

Google Workspace MX records: Name Priority Value @ 1 ASPMX.L.GOOGLE.COM @ 5 ALT1.ASPMX.L.GOOGLE.COM @ 5 ALT2.ASPMX.L.GOOGLE.COM @ 10 ALT3.ASPMX.L.GOOGLE.COM @ 10 ALT4.ASPMX.L.GOOGLE.COM
Zoho Mail MX records: Name Priority Value @ 10 mx.zoho.in @ 20 mx2.zoho.in @ 50 mx3.zoho.in
Microsoft 365 MX record: Name Priority Value @ 0 yourdomain-com.mail.protection.outlook.com (The exact value is unique to your Microsoft 365 tenant)

Setting up MX records

Step 1: Log into your domain registrar or DNS provider (Cloudflare, GoDaddy, Namecheap, etc.). Step 2: Find the DNS management section. Step 3: Delete any existing MX records (old records will conflict). Step 4: Add the new MX records from your email provider's documentation. Step 5: Save the changes. Step 6: Verify with MXToolbox (mxtoolbox.com/mx.aspx).

For Google Workspace, the exact MX records are provided during the Gmail setup wizard in Google Admin Console. For other providers, the records are in their knowledge base or onboarding documentation.

  • Always delete old MX records before adding new ones — conflicting records cause mail delivery failures.
  • On Cloudflare, MX records should be set to 'DNS only' (grey cloud) — not proxied.
  • MX record TTL: 3600 seconds (1 hour) is standard for most setups.

Diagnosing MX record problems

If email is not being received, check your MX records first. Common problems: no MX records exist (email has nowhere to go), conflicting MX records (old provider's records still present alongside new ones), typo in the mail server hostname, wrong priority values (non-critical, but can cause slower delivery if primary is unavailable).

Use MXToolbox (mxtoolbox.com/mx.aspx) to look up your MX records from outside your network. It will show exactly what the internet sees for your domain's MX configuration and flag any issues.

  • MXToolbox lookup: enter your domain and click MX Lookup for an instant verification.
  • If records look correct but mail still isn't arriving, check with your email provider — the issue may be account-level, not DNS.
  • After changing MX records, the old records may still be cached globally for up to 48 hours.