PowerMTA - IP Rotation Setup
IP Rotation in PMTAcore
IP rotation distributes outgoing emails across multiple IP addresses on the same server. PMTAcore automates the entire setup — it detects all IPs on your server, lets you assign a domain to each one, and configures PowerMTA's virtual MTA pool automatically.
How It Works in PMTAcore
When you select IP Rotation mode during installation, PMTAcore:
- Detects all public IPv4 addresses on your server via SSH
- Shows you each IP and lets you assign a domain to it (e.g. IP1 → mail1.yourdomain.com, IP2 → mail2.yourdomain.com)
- Installs PowerMTA with a standard single-domain config first
- Then rewrites the PowerMTA virtualhost configuration to create a virtual MTA for each IP
- Groups all virtual MTAs into a rotation pool
- PowerMTA automatically cycles through all IPs in round-robin when sending
Requirements
- PMTAcore with a paid license
- A server running AlmaLinux 8/9 or Rocky Linux 8/9
- At least 2 IP addresses assigned to the server (IP rotation requires 2+ IPs)
- A domain (or subdomain) for each IP address
- Access to DNS settings for your domain
Step 1: Add Multiple IPs to Your Server
Before starting, make sure your server has multiple IPs. Add them through your cloud provider:
- Linode — Instance → Networking → Add an IP Address
- Vultr — Instance → Settings → IPv4 → Add Another IPv4 Address
- DigitalOcean — Use Reserved IPs or contact support
- Custom servers — Contact your hosting provider
Step 2: Start Installation with IP Rotation
- Go to PowerMTA Installation and select your server.
- PMTAcore automatically detects all IPs on the server and lists them.
- Under Installation Mode, select IP Rotation (this option only appears if the server has 2+ IPs).
- For each IP, enter the domain you want to assign to it. The first IP is marked as PRIMARY. Example:
- 192.168.1.10 → mail.yourdomain.com (PRIMARY)
- 192.168.1.11 → mail2.yourdomain.com
- 192.168.1.12 → mail3.yourdomain.com
- Select the PowerMTA Version.
- Enter SMTP Credentials (username and password).
- Click Start Installation.
Step 3: What Happens During Installation
PMTAcore runs two phases:
- Base Installation — Installs PowerMTA with the primary domain, same as single domain setup.
- IP Rotation Configuration — Rewrites the PowerMTA virtualhost.txt to include all IPs with their assigned domains in a rotation pool. Each IP gets its own virtual MTA, and all are grouped into a pool for round-robin sending.
You see real-time progress for both phases in the output area.
Step 4: DNS Records
After installation, you need DNS records for every IP:
- A Records — Each domain must point to its corresponding IP (mail.yourdomain.com → IP1, mail2.yourdomain.com → IP2, etc.)
- PTR Records (Reverse DNS) — Each IP must have reverse DNS pointing to its assigned domain. Set this from your cloud provider dashboard.
- SPF Record — Must include ALL IPs:
v=spf1 ip4:IP1 ip4:IP2 ip4:IP3 -all - DKIM Record — One DKIM key covers all IPs (it is per-domain, not per-IP). Add the public key shown after installation.
- DMARC Record — One record at _dmarc.yourdomain.com, same as single domain.
How the Rotation Works
Once configured, PowerMTA automatically distributes outgoing emails across all IPs in the pool. When you send a campaign through the server, each email goes out from a different IP in round-robin order. You do not need to do anything special when sending — the rotation is handled entirely by PowerMTA.
How Many IPs?
| Daily Volume | Recommended IPs |
|---|---|
| Under 50,000 | 1-2 (rotation optional) |
| 50,000 - 100,000 | 3-5 |
| 100,000 - 500,000 | 5-10 |
| 500,000+ | 10+ across multiple servers |
IP Warm-Up
New IPs have no reputation. Sending high volume immediately will get them blocked. Warm up gradually:
- Day 1-3: 500-1,000 emails per IP per day
- Day 4-7: 2,000-5,000 per IP per day
- Day 8-14: 10,000-20,000 per IP per day
- Day 15+: Gradually increase to full volume
Send to your most engaged recipients first during warm-up.
Monitoring
Check your IPs regularly on blacklist monitoring tools (MXToolbox, MultiRBL). If one IP gets blacklisted, you can remove it from the rotation in the PMTA config while the others continue sending normally. This is the main advantage of rotation — one bad IP does not take down your entire sending.