Install PowerMTA 5.0r3 on Rocky Linux 8 for Better Email Delivery

Prerequisites

Before you begin, ensure that you have the following:

A Rocky Linux 8 instance with root or sudo access.
PowerMTA 5.0r3 RPM file.
A valid PMTA 5.0r3 License (you can purchase the license here).
Basic knowledge of command-line Linux operations.

Suggested : How to Install PowerMTA 4.5r1 on CentOS 7

Steps to Install PowerMTA 5.0r3 on Rocky Linux 8

1. Update the System

First, ensure that your system is up-to-date by running:

sudo dnf update -y

2. Disable SELinux (Optional)

Sometimes, SELinux can cause issues with PowerMTA. To disable it temporarily and make it permissive, run:

sudo setenforce 0
sudo sed -i 's/^SELINUX=enforcing/SELINUX=permissive/' /etc/selinux/config

3. Install Dependencies

To make sure all required dependencies are installed, run the following command:

sudo dnf install -y wget net-tools tar vim

4. Set Hostname

Next, configure your server’s hostname. Replace mail.domain.xyz with your actual domain:

hostnamectl set-hostname mail.domain.xyz

5. Install PowerMTA

Now, let’s install PowerMTA 5.0r3. Start by downloading and installing the RPM package:

cd /root/
sudo dnf install -y PowerMTA-5.0r3.rpm  - Buy Sparkpost PowerMTA License for Sending Bulk Emails

Note: If needed, you can also install PowerMTA without weak dependencies by running:

sudo dnf install -y --setopt=install_weak_deps=False PowerMTA-5.0r3.rpm

6. Stop PMTA Services

Stop any running PowerMTA services to avoid conflicts:

service pmta stop
service pmtahttp stop
sudo systemctl status pmta

7. Remove Original Files

Sometimes, PowerMTA installs with default files that may need to be replaced. Remove the existing files:

rm -rf /usr/sbin/pmtad
rm -rf /usr/sbin/pmtahttpd

8. Copy Modified Config Files

Copy the required modified and configuration files from your local directory to the system directories:

cd /root/usr/sbin
cp * /usr/sbin

cd /root/etc/pmta
cp * /etc/pmta

chmod 777 /usr/sbin/pmtad
chmod 777 /usr/sbin/pmtahttpd

9. Open Ports for PowerMTA

PowerMTA requires certain ports to be open for smooth operation. The most common ports are 25, 587, 2525, and the management port (default: 1234). Open these ports in your firewall:

sudo firewall-cmd --permanent --add-port=25/tcp
sudo firewall-cmd --permanent --add-port=587/tcp
sudo firewall-cmd --permanent --add-port=2525/tcp
sudo firewall-cmd --permanent --add-port=1234/tcp
sudo firewall-cmd --reload

10. Generate DKIM Keys

Generate the DKIM keys necessary for email authentication:

cd /etc/pmta
openssl genrsa -out dkim.private.key 1024 && openssl rsa -in dkim.private.key -out dkim.public.key -pubout -outform PEM

11. Increase Max Open Files

For optimal performance, increase the number of open files that PowerMTA can use:

sysctl -w fs.file-max=262144

12. Reboot the Server

After making all necessary changes, reboot your server:

sudo reboot

Enable and Start PowerMTA

Once your server reboots, enable and start the PowerMTA service to begin sending emails:

sudo systemctl enable pmta
sudo systemctl start pmta
sudo systemctl status pmta

Debugging PowerMTA

If PowerMTA is not running as expected, you can debug the service using the following command:

/usr/sbin/pmtad --debug

Also, if you find that ports like 25 or 2525 are already in use, you can identify and kill the conflicting processes using:

netstat -tulpn | grep :2525
netstat -tulpn | grep :25
kill -9 [PID]


Related : How to Use Amazon WorkMail for Bulk Email Sending 📩🚀

Removing PowerMTA Email Queue

If you need to clear the PowerMTA email queue, use the following commands:

service pmta stop
cd /var/spool/pmta/
rm -rf *
service pmta start
service pmta restart
service pmtahttp restart
service pmta reload

Configure DNS Records (DKIM, SPF, DMARC)

After setting up PowerMTA, it’s crucial to configure your DNS records for authentication.

DKIM

Add the following DKIM record to your DNS (replace dkim.public.key.pem with your actual DKIM public key):

default._domainkey.domain.xyz
v=DKIM1; k=rsa; p=(paste public key here)

SPF

Ensure you have the proper SPF record to authorize your mail server’s IP:

domainname.xyz
v=spf1 a mx ip4:xx.xx.xx.xx ~all

DMARC

Add a DMARC record to your DNS for email validation:

_dmarc.domain.xyz
v=DMARC1; p=none;

MX Records

Finally, add the necessary MX records for email routing.

Changing rDNS (PTR Record)

To improve email deliverability, configure the reverse DNS (rDNS). The process for this varies by cloud provider, but in most cases, you can edit the network settings in the cloud panel. For example, in Linode, you can change it from the network tab of the instance.

Conclusion

By following this guide, you will have successfully installed and configured PowerMTA 5.0r3 on Rocky Linux 8. With proper configuration of DKIM, SPF, and DMARC, you can ensure your email server operates effectively and securely, avoiding common email deliverability issues.

For your PMTA 5.0r3 License, remember to purchase here.

How to Install PowerMTA 5.0r3 on Rocky Linux 8

A Simple Guide to Installing PowerMTA on Rocky Linux 8 for Efficient Email Delivery