Email marketing is one of the most effective ways to reach a large audience, but many struggle with deliverability when using cloud servers. DigitalOcean, a popular cloud hosting provider, can be optimized for bulk email sending if set up correctly. In this guide, we’ll cover how to configure DigitalOcean for email marketing, unlock Port 25, and ensure high deliverability.
Why Use DigitalOcean for Bulk Emailing?
DigitalOcean provides powerful cloud servers, competitive pricing, and flexibility, making it an excellent choice for hosting an SMTP server. However, sending bulk emails requires additional configuration, as DigitalOcean blocks Port 25 by default to prevent spam.
Benefits of Using DigitalOcean for Bulk Emails:
✔️ Affordable cloud hosting options
✔️ Scalable resources for growing email lists
✔️ Full control over email configuration
✔️ Ability to set up dedicated SMTP servers
Step 1: Setting Up a DigitalOcean Droplet
To start sending bulk emails, you first need a DigitalOcean Droplet (cloud server).
- Sign up for DigitalOcean – If you don’t have an account, create one. You can get $200 credit with a DigitalOcean Port 25 Open Account.
- Create a Droplet – Choose Ubuntu as the operating system for stability.
- Select a Plan – A basic plan is fine for small email lists, but opt for a higher-tier Droplet for better performance.
- Set Up Your Domain – Configure your domain with DigitalOcean to send authenticated emails.
Step 2: Unlock Port 25 for Email Sending
DigitalOcean blocks Port 25 by default to prevent spam. To send bulk emails, you need to unblock it.
🔹 Option 1: Use a DigitalOcean Port 25 Open Account. This saves time and effort.
🔹 Option 2: Request DigitalOcean support to unblock Port 25. You will need to provide a valid reason, such as running a legitimate email marketing campaign.
If Port 25 remains blocked, you can use Ports 587 or 465 with an external SMTP relay service.
Step 3: Install & Configure an SMTP Server
Once your droplet is ready, you need to set up an SMTP server. Postfix and PowerMTA are the most popular choices.
Installing Postfix (Free SMTP Server)
Run the following commands on your server:
sudo apt update
sudo apt install postfix -y
During installation, select Internet Site and enter your domain name.
Installing PowerMTA (Premium SMTP Server)
PowerMTA provides better email deliverability and IP rotation. If you’re serious about bulk emailing, investing in PowerMTA is recommended. You can get PowerMTA licenses from trusted providers.
Step 4: Configure SPF, DKIM, and DMARC
To improve email deliverability and avoid spam filters, set up email authentication records:
✔ SPF Record: Allows only your server to send emails on your behalf.
✔ DKIM Record: Encrypts and verifies your email signatures.
✔ DMARC Record: Defines rules for handling unauthenticated emails.
Example SPF Record (Add to DNS):
v=spf1 ip4:YOUR_SERVER_IP -all
Example DKIM & DMARC configurations depend on your SMTP software and domain provider.
Step 5: Use a Mail Sending Software
For bulk emailing, you need a robust mail sending application. Here are some options:
✔️ Mautic (Free, self-hosted marketing automation)
✔️ MailWizz (Affordable one-time purchase)
✔️ Interspire (Premium bulk email software)
These tools allow you to schedule, track, and optimize email campaigns.
Step 6: Monitor & Improve Deliverability
Even with the right setup, deliverability is key. Follow these best practices:
✅ Warm Up Your IP – Don’t send thousands of emails instantly. Gradually increase volume to build a good reputation.
✅ Check Spam Score – Use tools like Mail-Tester to analyze your email spam score.
✅ Monitor Bounce Rates – High bounce rates can lead to email blacklisting.
✅ Use Dedicated IPs – A dedicated IP improves sender reputation.
Alternative: Use a Third-Party SMTP Relay
If you don’t want to set up your own SMTP server, consider using a third-party SMTP relay like:
✔ Amazon SES (Affordable with high deliverability)
✔ Mailgun (Good for developers)
✔ SendGrid (Easy integration with marketing tools)
These services provide pre-configured SMTP servers to send bulk emails without hassle.
Conclusion
Sending bulk emails from DigitalOcean requires proper configuration, Port 25 access, and authentication settings to ensure high deliverability. Using a DigitalOcean Port 25 Open Account simplifies the process and allows smooth email sending. Follow this guide to set up your SMTP server, configure security settings, and optimize your email campaigns effectively.
For more insights on email marketing, check out our Email Marketing Guides.
