Doc Summary
Email deliverability determines whether your emails reach the recipient’s inbox.
SPF, DKIM and DMARC are authentication methods that help receiving mail servers verify that your emails are legitimate.
Correct configuration is essential for reliable email delivery.
Why Email Authentication Is Important #
Without proper authentication:
- Emails may be marked as spam
- Emails may be rejected entirely
- Your domain reputation may be damaged
Most modern mail providers require SPF, DKIM and DMARC.
Where to Manage Email Deliverability in cPanel #
- Log in to cPanel
- Go to the Email section
- Click Email Deliverability
This page shows the current authentication status for your domain.
SPF Explained #
SPF stands for Sender Policy Framework.
SPF:
- Defines which servers are allowed to send email for your domain
- Is stored as a DNS TXT record
- Helps prevent sender spoofing
If an email is sent from an unauthorized server, it may be rejected or marked as spam.
DKIM Explained #
DKIM stands for DomainKeys Identified Mail.
DKIM:
- Adds a cryptographic signature to outgoing emails
- Allows receiving servers to verify message integrity
- Confirms the email was not modified in transit
DKIM uses a DNS record and works automatically once enabled.
DMARC Explained #
DMARC stands for Domain-based Message Authentication, Reporting and Conformance.
DMARC:
- Combines SPF and DKIM results
- Defines what happens when authentication fails
- Allows domain owners to receive reports
DMARC policies control whether emails are monitored, quarantined or rejected.
Default Configuration at ProRedLine #
For supported domains:
- SPF is automatically generated
- DKIM is enabled by default
- DMARC is set to a safe monitoring policy
This setup is suitable for most users.
When Manual Changes Are Required #
Manual changes may be needed if:
- You send email through external services
- You use third-party newsletters or CRM tools
- Multiple mail providers send on behalf of your domain
In these cases, SPF records must be adjusted carefully.
Common Mistakes #
- Creating multiple SPF records
- Removing DKIM records
- Using strict DMARC policies too early
- Forgetting to include external mail services
These mistakes often cause email delivery failures.
Role of Webmail and Email Clients #
Webmail clients such as Roundcube:
- Do not control SPF, DKIM or DMARC
- Only display email after it is delivered
Authentication happens before emails reach the inbox.
Responsibility Notice #
You are responsible for:
- Maintaining correct DNS records
- Adding external mail services properly
- Monitoring deliverability after changes
ProRedLine does not automatically correct custom email configurations.
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