Understanding Restricted Domain Email Blocking
What Restricted Domain Blocking Does
Your CRM includes a security feature that automatically prevents emails from being sent to certain recipient email domains. This check happens immediately before an email would leave the system. If a contact's email domain (the part after the @ symbol) is invalid or appears on a restricted list for security reasons, the CRM will block the send entirely—it won't attempt delivery.
Why This Feature Exists
This protection serves several important purposes:
- Preserves Your Sender Reputation: By stopping emails that would likely bounce or be rejected, it helps maintain your email deliverability rates.
- Reduces Security Risks: It prevents communication with domains that are known to be problematic or restricted for security concerns.
- Saves Resources: It avoids wasting email credits or bandwidth on sends that would fail anyway.
How It Works
The process is automatic and happens in three steps:
- Whenever an email is about to be sent—whether from a campaign, workflow, or manual message—the CRM validates the recipient's email domain.
- If the domain is invalid or restricted, the system blocks the send before it can leave the CRM.
- The contact's email address becomes unusable for outbound communication until it is updated to a valid, permitted domain.
What You'll See When an Address Is Blocked
When you view or edit a contact with a blocked email address, a warning message appears directly beneath the Email field. The warning states that the email address is invalid because the domain is restricted for security reasons.
How to Fix a Blocked Email Address
Step 1: Verify the Address
First, check if the email address was entered incorrectly. Look for common typos, especially in the domain name (the part after the @ symbol).
Step 2: Update the Contact
If the address is incorrect, update the contact's record with a valid email address on a permitted domain. Once saved, outbound email sending to that contact will function normally again.
Step 3: Contact Support for Critical Domains
If you believe a legitimate business domain is being incorrectly blocked, you can contact Support. Be prepared to provide:
- The specific recipient domain (e.g., company.com).
- Where you encountered the warning (e.g., Contact record, Campaigns).
- Your sub-account name or ID.
- Your configured sending method.
Important Note: There is no user-accessible setting to override or bypass this block within the CRM. The email address must be changed to a permitted one for sending to resume.
Common Questions
Can I send an email if I see the warning?
No. The CRM will not attempt to send any email—including campaign emails, workflow emails, or manual sends—to an address with a blocked domain.
Where does the warning appear?
The inline warning appears under the Email field on a contact's record whenever that address is loaded or newly entered.
Does a blocked send count as a bounce?
No. Since the email is never actually dispatched from the system, it does not generate a bounce event. This helps protect your sender reputation.
How can I prevent this?
Use email verification services, form validation, or double opt-in processes when collecting email addresses to ensure they are valid from the start. Also, promptly correct any obvious typos in domain names.
Does this apply to all ways I send email?
Yes. The validation runs regardless of whether you use the built-in CRM email system, Mailgun, or a custom SMTP integration.