When sending cold emails, one of the biggest challenges is ensuring your messages land in the inbox, not the spam folder.
One powerful (and often overlooked) tactic is Matching ESP - sending emails to recipients using the same email service provider they use.
In other words:
If your prospect uses Google Workspace, and you send the email from a Google Workspace mailbox, your message has a higher chance of being trusted and delivered to the inbox.
Why Matching ESP Matters
Email providers like Google and Microsoft run complex security checks to verify whether incoming emails are legitimate. When both sender and recipient are on the same ecosystem, the communication is more trusted because:
Server-to-server communication is recognized as “safe”
Authentication workflows (SPF / DKIM / DMARC) pass more easily
Spam filters see fewer red flags
Delivery latency (time to inbox) is reduced
Result:
✅ Better inbox placement
✅ Higher open & reply rates
✅ Lower bounce and spam rates
How Matching ESP Works
Matching ESP analyzes the recipient’s email domain to determine whether their inbox is hosted on Google or Microsoft (or something else).
Example:
If the lead’s email is [email protected], the system checks the domain company.com and looks up its MX DNS records to identify the email provider.
How to Enable Matching ESP
You can enable Matching ESP at two levels:
1. Team Level
Enable once → applies to all campaigns.
Path:
Settings → Sending settings → Team tab
You can always disable it on specific campaigns later if needed.
2. Campaign Level
Enable Matching ESP only for a specific campaign.
Path:
Campaign → General Settings → Matching ESP toggle
Important Requirement
To use Matching ESP, your workspace must have:
At least 1 Google mailbox, and
At least 1 Microsoft mailbox connected and active.
This allows the system to choose the right sender depending on the lead's email provider.
What Happens When the Campaign Runs
A lead enters the campaign
The system checks the lead’s domain MX record to identify:
Google
Microsoft
Other / Unknown provider
When it's time to send the email:
If we can match the provider → we choose a sender with the same ESP
If we cannot match → the email is sent normally using your default sender pool
Example Logic
Lead’s Email Provider | Do you have a matching sender? | Result |
Google Workspace | Yes ✅ | Sent via Google sender |
Google Workspace | No ❌ | Sent via any default sender |
Microsoft 365 | Yes ✅ | Sent via Microsoft sender |
Unknown / Other | — | Sent normally |
Why This Improves Deliverability (In Simple Terms)
When Gmail emails Gmail → inbox trust is higher.
When Outlook emails Outlook → inbox trust is higher.
It’s like sending a message inside the same network, instead of from the outside.