With SPAM filtering build into the latest version of Exchange and all sorts of firewalls now available to scan for viruses, malware and other internet-borne undesirables, it may seem like a bit of a backward step to use an external (or “cloud” hosted) SPAM and malware filter for your incoming and outgoing emails so is it really worth it? What advantages do they provide? What are the downsides?
What is an external SPAM filter?
An external SPAM filter is, as its name suggests, an email filter which is hosted outside of your organisation. Typically it will process emails (in and out) for hundreds, if not thousands, of clients monitoring all emails for signs of SPAM or malicious content and then sending only the “clean” emails on to their destinations. It is a cheap and efficient way of making sure (as sure as you can be) that SPAM and/or malicious emails don’t get delivered to your users.
Potentially malicious emails do not get anywhere near your network
Because the filter is hosted outside of your organisation (most often in a different country entirely), the emails which have malicious or other undesirable content do not come anywhere near your servers. If you use an on-premise filter (IE. one installed on a server in your organisation) any undesirable emails will, in some form, be on your equipment. You have no way of knowing if, by some unknown process, any (or all) of these potentially dangerous emails could be released and cause havoc on your servers. Furthermore, you are responsible for making sure the filters are kept up to date and the hardware is sufficiently powerful to keep things moving.
Less chance of your public IP address being “black listed”
At any time, the IP address assigned to your internet connection can be put onto what is known as a blacklist. When this happens, some email servers will refuse to send emails to your server or accept emails from your server until your address is de-listed. This can take time. Using an external filtering service gets around this potential problem. Since email coming from your servers appears to come from the filtering server, your IP address shouldn’t be blacklisted. Furthermore, emails destined for your server will go to the filtering service’s IP address which should never be blacklisted so everyone’s happy!
Provides an email queue should your internet connection or email server (or both) go down
Without an external filtering service, any emails sent to your email server while the internet connection is down (or the email server itself is down) will be returned to the sender as undeliverable. This can be quite an annoying situation, particularly if the non-delivery report itself goes missing on its way back to the sender (this can, and often does, happen). To overcome this, most email filtering services provide a queue which will hold emails for 3 to 5 days (some up to 10 days!) in the event that emails cannot get to their destinations. This gives you (or your IT provider) ample opportunity to fix the problem without losing any emails. This feature also comes into play when changing internet service providers.
Performance, Availability and Features
Like all “cloud” services, you are at the mercy or the provider in terms of performance, availability and features offered. If their servers or internet connection go slow, so too does your email delivery! If their servers or internet connection go down, your email delivery stops altogether! If they decide to change or remove a feature that you have come to rely on then there is nothing you can do.
All of your external email goes through their servers and could, potentially, be scanned for more than SPAM or malware (think words or phrases like “bomb” or “terrorism”). If your company deals in sensitive information then you may want to think twice about using an external filtering service, despite the advantages. Furthermore, because these services are often hosted overseas, you may be bound by their laws which could be radically different from those in your country.
UPBEAT Business Computing can advise as to whether a “cloud” hosted SPAM filter is right for your business and we can get one set up for you without impacting on your business email delivery. Give us a call to find out more.