Outbound Email Spam Filtering for Web Hosting Providers, ISP’s and High Volume Senders

We prevent spammy customers from getting your mail servers blacklisted

Cloud-based protection

No hardware to buy. No software to install. No maintenance.

High deliverability rate

Keeps your IP addresses off of blacklists and keeps your customers happy.

Spam blocking

Keeps your customers’ spam from getting out on the internet and causing you problems.

Cost effective

Most competitive prices. No long-term contracts. Leave at any time.

Spam alerting

When outgoing spam is detected, you’re alerted so you can shut it down.

Redundant infrastructure

Your customers expect you to be up and running all the time. So do ours.

Web host are not in control of the email they send

As a web hosting provider you probably find yourself offering outbound SMTP services. You’re sending out emails for your customers who all have different intentions and varying degrees of security.

Having thousands of customers sending out messages from your IP addresses and not being in control of what they send comes with its risks. If just one of your sites gets exploited and starts sending out spam it will damage your IP addresses and your reputation.

If you’re hosting websites you’re probably sending out spam

According to Statista, 54% of global email in September 2018 was spam. Other research companies estimate that spam comprises as much as 73% of email traffic. To complicate matters, it’s estimated that 88% of all spam is sent from botnets (networks of compromised computers).

The bottom line is, whether intentionally or not, if you’re hosting websites, VPC’s, or shared hosting there’s a pretty good chance you’re customers are sending out spam. And if your mail server or IP addresses get blacklisted, that could bring down you entire company. Outgoing spam is too serious a problem to ignore.

Outbound Mail Filter is the buffer you need to keep you up and running

What you need is someone to run interference for you. A service that can scan your outgoing email, block the spam and notify you of the offending party. And more importantly, not blacklist you or shut you down should spam be detected.

OutboundEmailFilter is a cloud-based SMTP relay service with spam filtering specifically designed for web hosting providers. It scans outgoing mail for spam. When spam is detected, it quarantines it and sends you an alert. It even includes rate limiting during a spam storm to keep your bandwidth from getting clogged.

The best insurance money can buy

OutboundEmailFilter requires no hardware, no plug-ins and just few software configuration changes. It works with any mail server or email service that supports SMTP authentication.

Whether you’re sending out 50,000 emails per month or a million emails per day, OutboundEmailFilter is the best insurance a hosting provider can buy. It’s designed for any size hosting provider and is offered at a price that makes it a no brainer.

Outbound Email Filter is fast, easy and affordable

No sales calls. No contracts. Up and running in ten minutes.


“Each of our Kentico CRM deployments depend on the reliablity and deleverability of the service. We highly recommend it to all our clients for the best inbox placement.”

Hilton Sher


“We have built our mailing list of professional sales people over the past 15 years and your service helps to deliver our messages reliably into the inbox.”

Jim Dunn


“We rely heavily on your smtp services to get our invoices and emails into our customers inboxes. Thanks for your great service and technical support.”


Roy Salvin

Join thousands of satisfied customers using our
email services globally.


10 Minute Deployment

You’ll be up and blocking outbound spam within 10 minutes of updating your DNS record.


24x7x365 Live Technical Support

As a web host, you’re probably proud of your customer service. So are we.


Frequently Asked Questions

Got a question? We’ve got answers. If you have some other questions, see our support center.

Why is outbound spam so hard for web hosts to stop?

For two reasons. The first is because web hosts don’t control what email their clients send out. The second reason, and the one that’s more challenging, is that web hosting customers themselves don’t always control what email they send out. It’s estimated that 88% of all spam is sent from botnets (networks of compromised computers). Well-meaning web hosting customers who have no intention of sending out spam, may in fact be unknowingly sending out spam.

What are the risks of having my email server(s) send out spam?

Should your email servers, knowingly or unknowingly, send out spam, your IP address(s)  and your domain(s) could both be placed on blacklists. And if ISPs see you as a repeat offender, ALL of the email coming from your email server(s) could be blocked from reaching their destination. A single spammy web hosting customer can shut down your email server(s) for all your customers, who may then decide to switch hosting providers.

What are the two most important things in stopping outbound spam?

You might think that stopping outbound spam is a one step process: stop outbound spam from getting out onto the web where it can be classified as spam. But, that’s only the first step. There’s one more step which is just as important and that’s finding the source of the spam and turning it off. Make sure whatever solution you choose to stop outbound spam comes with spam alerting.

What should a web host look for in an outbound email filtering service?

Of course an outbound email filtering service should block outbound spam. Additionally, the solution should include the following:

  • Spam alerting so you can shut down the spam at the origin
  • A cloud-based service so spam can be blocked before it hits the web
  • High deliverability rates with clean IPs to keep your customers happy
  • Rate limiting: in case your account is compromised by a virus
  • Scalable: it should be able to handle 10 thousand or 10 million emails
  • Fast: it shouldn’t take more than 10 minutes to be up and running
  • Easy: it shouldn’t require any hardware, software or ongoing maintenance
  • Affordable: it shouldn’t require lengthy contracts or per-server fees
  • Redundant infrastructure so your email is always being relayed
  • Excellent customer service: 24/7/365 live support
What's the difference between smtp relay and outbound email filtering?

SMTP relay is a service that routes email through a trusted 3rd party to deliver bulk email. It’s mostly used for sending large batches of emails (e.g., newsletters). In general, SMTP relay services will NOT accept spam coming from your email server(s). They will behave just like ISPs and cut off your outbound email altogether. In essence, they’ll blacklist you. Outbound email filtering by contrast actually decisions your spam while allowing legitimate email to still flow without the spam getting out on the web. And since outbound email filtering doesn’t cut you off or blacklist you, sending out spam, even unknowingly, won’t get you shut down.

What do you scan for on outbound email?

Outbound email filtering

Is there a way to get outbound email filtering that's fast, easy and affordable?

Happily yes. OutboundEmailFilter.com provides enterprise-class outbound spam filtering at small business prices. There are no sales calls, no contracts, and you’re up and running in 10 minutes. Click here to get started today.