Web Hosted Email Filter

Usually placed as part of a cloud-based solution, a web hosted email filter is a Software-as-a-Service (SaaS) filtering service hosted on a remote server.

It has a number of advantages over on-premises email filters inasmuch as a hosted email filter has fewer (if any) maintenance expenses, can simply be scaled up or down depending on the changing environment of your business, and is generally cheaper than an on-site solution.

Most service suppliers host their email filtering services in high security data centers, have SLAs in place for when outages happen, and supply expert support and monitoring 24/7. For many SMBs, a hosted email filter is the perfect spam filtering solution, as it leverages cloud-based services to provide an enterprise-class solution for businesses on a restrictive budget.

That depends on the email filtering service you opt for. Not all hosted email filtering services are the same, and some lack important mechanisms that (in our opinion) sacrifice online security for performance. Naturally, the filtering settings set by a system administrator will also influence how effective a hosted email filter is at protecting a business from email-borne threats also.

For this reason, the best hosted email filtering services are those which are simple to use. A hosted email filter can have all the “granularity” in the world to configure different settings to different users depending on their roles; but if it is too difficult to apply different settings to different users – and gaps in the filtering parameters permit spam emails to enter the business – the high level of granularity is of little value.

When you implement a cloud-based email filtering service, the filtering process is conducted in the cloud – eliminating any strain on the business´s CPU or mail server. Therefore, it is difficult to understand why some service suppliers omit to include resource-intensive features such as greylisting and outbound filtering in their services – unless it is to save resources at their end.

Greylisting in particular is a crucial online security mechanism. Most email filtering services use SURBL filters to prevent the delivery of emails from IP addresses from which spam email is known to have originated. What greylisting does is return every email and request it is sent again. Spammers´ servers are usually too busy to respond to the request, so the email never gets sent again.

In this manner, a hosted email filter with greylisting prevents the sending of spam emails from not-yet-known sources of spam – giving businesses a higher level of security against email-borne threats such as phishing, malware and ransomware without any loss of network performance. The greylisting process can lead to short delays in email receipt, which is why we also include a whitelisting feature in our hosted email filter in order to permit emails from trusted senders to get around the greylisting security mechanism.