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Security Scanning FAQ

E-mail Security Scanning FAQ -

This page aims to answer questions we are frequently asked about our e-mail security scanning (spam and anti virus filtering) service. If you have any questions which are not answered here, please send an e-mail to support@lucidnetworks.co.uk

How does the service work? -

Our systems scan all your incoming messages and apply a series of automated tests, which help establish how likely the message is to contain spam, or whether it contains a virus. Based upon the outcome of those tests, we either reject the message immediately, or "tag" the message within the headers (not usually visible to you, but visible to your e-mail software) so that you can filter it into a junk mail folder to review later.

Whenever we reject a message because we think it is spam, or contains a virus, we always send back a "bounce" message to the sender, which tells them why the message has been rejected. That way, if the message is genuine, the sender gets an opportunity to correct the problem and re-send it, rather than the message silently disappearing into a quarantine folder.

First, we apply a test to see whether your e-mail has been sent from a mail server which is on a "DNS Blacklist" or DNSBL. These lists are sometimes also called "realtime black hole lists", or RBLs. DNSBLs are lists which are maintained by independent organisations (we have no control over them), which list the internet addresses of e-mail servers which have been known to send spam e-mail. (click here for a more complete explanation of DNSBL's). If the sending mail server is on one of those lists, or if the message is found to contain a virus, then we reject the message outright, and send back a bounce message.

We also compare each e-mail passing through the system against a large number of pre-defined tests, which are used to determine how likely the e-mail is to be spam. If we think the e-mail might be spam, then we still deliver it to you, but we "tag" it, so you can filter it into a folder in your e-mail software. If we think the mail is very likely to be spam, we reject it, with a bounce message.

I've not received an e-mail I was expecting. Has it been deleted by the spam filtering system? -

No, we never delete e-mail. If the mail contained a virus, or we thought it was very likely to be spam, we would have rejected it, and the sender would have received a bounce message indicating why the message was rejected. Contact the sender to find out. If we thought the e-mail MIGHT be spam, we would have delivered it to you, with a tag in the headers. Check your e-mail software's Junk Mail folder.