VPS for Email Marketing: 14 Providers, Their Port 25 Rules and What to Pick
Cem Hurturk, Founder of Octeth
Updated First published
Search for a VPS for email marketing and you will find lists that recommend DigitalOcean, Linode, AWS and Google Cloud. All four block outbound port 25 by default, and those lists rarely say so. You find out after you have installed everything and your first campaign never leaves the server.
I have been running email infrastructure since 1999. The provider matters less than one earlier decision: will your VPS hand mail to a relay such as Amazon SES, or will it run its own mail server and deliver straight to Gmail and Outlook? This page explains that choice, then compares 14 providers on the points that matter for email, all checked against their official pages on 2026-10-03.
Short answer
| If you | Then |
|---|---|
| Run an email marketing app and send through a relay (Amazon SES, Mailgun, SendGrid) | Almost any VPS works. Pick on price and location: Hetzner, Vultr, OVHcloud, UpCloud |
| Want to run your own mail server (Postfix, PowerMTA) | You need port 25, reverse DNS and extra IPs: OVHcloud and Kamatera allow port 25 by default. Hetzner, AWS EC2, Vultr and UpCloud open it on request |
| Want neither the server nor the IP reputation work | A managed delivery service, such as Octeth's dedicated-IP delivery |
| Are on DigitalOcean or Google Cloud | Use a relay. Neither documents a way to unblock port 25 for regular accounts |
Relay or your own mail server: decide this first
With a relay, your email marketing app runs on the VPS and hands every message to a service such as Amazon SES over SMTP port 587 or 465, or over an HTTPS API. The relay delivers to the inbox providers from its own reputable IPs. Port 25 does not matter, and most VPS providers allow 587. Amazon SES also accepts SMTP on ports 2587 and 2465 for providers that block the standard ports. Cost: $0.10 to $0.16 per 1,000 emails on SES. This is the right choice for most senders.
With your own MTA, the VPS runs a mail transfer agent such as Postfix or PowerMTA and connects to Gmail, Outlook and Yahoo directly on port 25. You gain full control and the lowest cost per email at very high volume. In exchange you need:
- Outbound port 25 open.
- Reverse DNS (PTR) on every sending IP, matching the hostname.
- Usually several IPs, to separate streams and spread volume.
- Weeks of IP warm-up before full volume.
- Bounce and feedback-loop processing, and blocklist monitoring.
- A provider whose acceptable use policy allows your kind of sending.
14 VPS providers compared for email
Checked against each provider's official documentation and pricing pages on 2026-10-03. Prices change often and some depend on term length or region.
| Provider | Port 25 by default | How to get it opened | Custom reverse DNS | Extra IPv4 | ~4 vCPU / 8 GB per month | Bulk email policy |
|---|---|---|---|---|---|---|
| OVHcloud VPS | Open (not in Local Zones) | Anti-spam system blocks it if spam is detected | Yes | $2.39/month | VPS-2 from $8.50 (12-month pricing) | Anti-spam monitoring |
| Kamatera | Open | Not needed | Yes, via support | $5/month beyond 4 | Configurator, varies | Verifiable opt-in required |
| Hostinger VPS | Open | Not needed | Yes | Not published | No 4 vCPU / 8 GB plan | Opt-in required, SMTP limited to 5 emails a minute |
| Contabo | Reported open, no official statement | Not documented | Yes | Not confirmed | Cloud VPS 4 from $5.28 (24-month offer, excl. VAT) | About 25 emails a minute limit |
| Hetzner Cloud | Blocked (25 and 465) | Request after 1 month and the first paid invoice | Yes | €3/month (floating) | CPX32 €35.99 (EU) | Not confirmed |
| AWS EC2 | Blocked | Request form per region, up to 48 hours | Yes, on Elastic IPs | About $3.65/month | c7i.xlarge about $130 (us-east-1) | Unsolicited mass email banned |
| Vultr | Blocked | Support ticket, not guaranteed | Yes | Not confirmed | $40 to $48 | Unsolicited mass email banned |
| UpCloud | Blocked on new accounts | Support request with ID or payment proof | Not confirmed | €3.47/month | €20 to €52 | Not confirmed |
| Scaleway | Blocked (25, 465, 587) | Self-serve after identity verification | Yes | About €3.65/month | About €37.74 | Not confirmed |
| InterServer | Blocked | Request after 1 month with no unpaid invoices | Yes | $3/month | 4 slices (2 cores, 8 GB) $12 | Mailing-only servers banned, double opt-in required |
| Linode (Akamai) | Restricted (25, 465, 587) on some newer accounts | Support request with your use case | Yes | Requires justification | $48 | Not confirmed |
| Microsoft Azure | Blocked except Enterprise Agreement subscriptions | Not available for most subscriptions | Yes | About $3.65/month | B4als v2 about $97 | Unsolicited bulk email banned |
| DigitalOcean | Blocked (25, 465, 587) | No documented unblock, recommends an email service | Automatic from the server name only | Free when assigned | $48 | Opt-in with consent proof required |
| Google Cloud | Blocked to external hosts | No documented unblock | Yes, after domain verification | Not confirmed | Not confirmed | Unsolicited mass email banned |
Three patterns stand out. Only OVHcloud, Kamatera and Hostinger state on an official page that port 25 is open by default. "Open" can still come with a sending cap: Hostinger allows 5 emails a minute and Contabo about 25. And even providers that allow bulk email require opt-in lists. A VPS is not a way around consent rules.
How big a VPS do you need?
Sizing depends on the application and your SMTP setup. As a reference, Octeth's published server requirements:
| Subscribers | vCPUs | RAM | Storage | Typical throughput |
|---|---|---|---|---|
| Up to 10,000 | 2 | 4 GB | 50 GB | 10,000 emails an hour |
| Up to 100,000 | 4 | 8 GB | 80 GB | 100,000 emails an hour |
| Up to 500,000 | 8 | 16 GB | 160 GB | 250,000 emails an hour |
| Up to 1,000,000 | 8 | 16 GB | 160 GB | 500,000 emails an hour |
| 1,000,000+ | 16 | 32 GB | 320 GB | 1,000,000+ emails an hour |
Throughput assumes a well-configured SMTP path. Use SSD storage, plan for database growth with your tracking data, and keep backups off the server. If you run your own MTA, put it on its own server or IPs, separate from the application.
Three setups that work
- App on a VPS, relay for sending. A 4 vCPU, 8 GB VPS from Hetzner, Vultr, OVHcloud or UpCloud, plus Amazon SES. For 400,000 emails a month that is roughly $40 to $50 for the server plus $40 to $64 for SES. Hosted email platforms charge about $430 to $800 a month at that volume (see our bulk email software comparison).
- App plus your own MTA. The application on one VPS and Postfix or PowerMTA on a provider that allows port 25 (OVHcloud, Kamatera) or opens it on request (Hetzner, AWS EC2), with reverse DNS and several IPs. Lowest cost per email at very high volume, and the most work.
- App on a VPS, managed dedicated IPs. The application on your VPS, with sending handled by a managed service on dedicated IPs. You keep your own platform and data, and someone else does warm-up, bounce processing and blocklist monitoring.
Before you send from a new VPS IP
- Check the IP against blocklists before you build on it, and ask for a replacement if it is listed.
- Set reverse DNS so the IP resolves to your mail hostname and back.
- Publish SPF, DKIM and DMARC for every sending domain. Our SPF record generator, DKIM generator and DMARC generator produce the records, and the SPF and DKIM checker verifies them. Use the MX inspector to check your domains.
- Warm up gradually. Start with your most engaged subscribers and ramp over four to six weeks. The IP warm-up planner builds a day-by-day schedule.
- Meet the bulk sender rules: Gmail, Yahoo and Outlook require authentication, one-click unsubscribe and a spam complaint rate under 0.3% for senders of 5,000 or more messages a day.
Where Octeth fits
Octeth is self-hosted email marketing software that installs in Docker on a clean Ubuntu 24.04 VPS:
- Runs on any of the providers above. Inbound it needs only web (80, 443) and SSH access, and it sends through the delivery servers you configure.
- Multiple delivery servers: Amazon SES, Mailgun, SendGrid, PowerMTA or any SMTP server, assigned per client group and per channel. A port 25 block only matters if you choose to run your own MTA.
- Octeth-operated delivery if you want dedicated IPs without running mail servers: managed warm-up, bounce and feedback-loop processing, blocklist and reputation monitoring.
- Multi-client accounts, journeys and a full API, for agencies and high-volume senders.
- Installation help from our team. We set up Octeth with our customers, and a full setup takes two to four weeks.
For a comparison of the software you could run on that VPS, see our self-hosted email marketing guide.
Frequently asked questions
Which VPS providers allow port 25?
As of October 2026, OVHcloud VPS, Kamatera and Hostinger state that outbound port 25 is open by default. Hostinger limits VPS sending to 5 emails a minute. Hetzner, AWS EC2, Vultr, UpCloud, Scaleway and InterServer open it on request or after verification.
Why is port 25 blocked on my VPS?
Providers block it to stop compromised or abusive servers from sending spam, which damages the reputation of their whole IP range. Most open it for established, verified customers with a legitimate use case.
Can I send email if port 25 is blocked?
Yes, through a relay. Your application sends to the relay on port 587 or 465, or through an API over HTTPS, and the relay delivers the mail. Amazon SES also accepts ports 2587 and 2465. DigitalOcean also blocks 465 and 587, so use an API or alternate port there.
Should I run my own mail server or use Amazon SES?
Use a relay unless you send at very high volume, need full control over IPs, or a relay will not accept your program. Your own MTA needs port 25, reverse DNS, warm-up and ongoing reputation work.
Is bulk email allowed on a VPS?
Opt-in bulk email is allowed by most providers. Unsolicited bulk email is banned everywhere. Some providers add conditions: InterServer bans servers used only for mailing, and Kamatera requires verifiable opt-in.
What VPS specs do I need for email marketing?
For about 100,000 subscribers, 4 vCPU, 8 GB of RAM and 80 GB of SSD storage. For up to a million, 8 vCPU and 16 GB. Your own MTA should run on separate resources.
How do I set reverse DNS on a VPS?
Most providers let you set the PTR record in their control panel once the forward DNS record exists. AWS needs a request form for Elastic IPs, and DigitalOcean derives it from the server name. Lightsail does not allow custom reverse DNS.
How long does IP warm-up take?
Plan on four to six weeks for a new dedicated IP, starting with small volumes to your most engaged subscribers and increasing daily as acceptance stays healthy.
Is a VPS cheaper than an email service provider?
At volume, yes. For 400,000 emails a month, a VPS plus Amazon SES costs about $80 to $115 a month, against about $430 to $800 on hosted platforms. The difference pays for the time you spend running it.