To eliminate the compromised account from sending a large amount of spam and hampering the reputation of the server, it helps to limit the number of emails a domain sends per hour. This tutorial will help to set a limit.
Note: Please note that sending a maximum number of emails each domain on an account may send per hour instead of the total number of emails sent from the account per hour.
- Set in WHM: These limits are configured within the WHM interface for each cPanel account.
- Hourly emails per domain: This setting specifies the maximum number of emails each domain on the account can send per hour. It’s the primary mechanism for controlling email volume at the domain level.
Navigate to WHM > Account Functions > Modify an Account.
Choose the account you want to modify.
Locate the “Maximum Hourly Email by Domain Relayed” setting.
If the “Unlimited (default)” option is selected, select the textbox option.
Mention the maximum number of emails for each domain under this account to be sent per hour.
“Please note that a value of 0 will be interpreted as no limit.”
Click on the “Save” button.
Enter the new plan name in the “Create a new plan with this name” textbox.
Click the “Proceed” button.
Note: The system doesn’t block additional messages at SMTP time if the domain reaches its limit. Rather, the system accepts and then handles additional messages per value of the “The percentage of email messages (above the accounts hourly maximum) to queue and retry for delivery “setting in “Tweak Settings”.
Email Account-Level Limits (Not Currently Built-In):
- Direct configuration not available: cPanel doesn’t offer a direct way to set email-sending limits for individual accounts.
- Possible workarounds:
- Exim configuration: If you have root access and expertise, you can potentially use Exim’s configuration options (e.g., recipients_max) to achieve some level of control. However, this requires advanced knowledge and might have implications.
- External services: Consider using third-party services cheap web hosting provider in USA specializing in email sending limits and authentication, which can integrate with cPanel and provide more granular control at the email account level.
- Server-wide limits: Your hosting provider might have overall server-wide email sending limits in place, regardless of individual account or domain settings.
- Temporary blocks: If a domain or account sends a large amount of spam or exceeds limits frequently, it might be temporarily blocked from sending emails.
- Sender reputation: High bounce rates or spam complaints can negatively impact your server’s sender reputation, leading to delivery issues even if you’re within the set limits.
- Monitor email activity: Regularly check email logs and statistics to identify unusual sending patterns or potential abuse.
- Implement SPF and DKIM: Set up SPF and DKIM authentication to enhance email deliverability and protect against spoofing.
- Educate users: Encourage responsible email practices and provide clear guidelines about sending limits to avoid unexpected blocks or issues.
I hope this comprehensive explanation is helpful!