ImerjaMail provides you the technical and cost benefits of using Open Source architecture within an easily administered web based managed service
ImerjaMail is a low cost business class email security solution that leverages the benefits of Open Source applications coupled with a specially developed easy to use management interface.
The service is hosted and managed by Imerja Limited, a specialist IT infrastructure and IT security service provider to organisations in both the public and commercial sectors, from small businesses with a handful of employees working on a single site through to large corporates with several thousand users spread over large campus, regional, national or international networks.
Whether or not you have an existing email anti virus and spam filtering product or service provided you have your own email system ImerjaMail is the ideal solution for ensuring the integrity of your email, defence against email born viruses and protection of your reputation.
ImerjaMail comprises of two main entities:
- Email Processing
- Reporting/Administration
Email Processing Servers validate emails being sent to and received from a subscribing customer’s email server. A pre-filter blocks unequivocal spam, Denial of Service Attacks and communications not conforming to the relevant RFC standards.
The validation process service starts by ensuring that the sender’s domain exists and is able to receive email. Then a wide range of public IP and domain sender blacklists are referenced to establish if the email has originated from a known spam site; these are challenged with temporary failure codes to ensure that the retries occur automatically and without the sender’s intervention.
Heuristic analysis, Bayesian filters are used to score spam messages, using over 900 propriety and Open Source detection rules co-ordinated by SpamAssassin.
This is complemented by a number of customised processes to help ImerjaMail to maintain a detection rate of more than 98%.
Outbound email is also spam-filtered, but with a different threshold level. This increases the accuracy of the spam filtering process and checks that spam is not being generated from the customer’s domain. This helps ensure that the customer is protected in the event that their system has been compromised and they are being used as a spam relay. If this was to occur not only will the customer’s systems and Internet Bandwidth be exhausted, but the email address is likely to be added to spam “Black Lists”, thereby potentially causing legitimate emails to be blocked by the recipients anti spam system.
Spam is scored and a score of greater than 15 would suggest that there is every indication that the message is spam. High scoring emails can be automatically deleted, while low scoring emails (greater than 7) can be quarantined. The parameters are configurable (within limits) by the Administrator.
The Administrator is also able to configure what action is triggered in the event that an email is quarantined. Options include forwarding the email with a warning in the subject line, forwarding the email as an attachment to a warning message and storing the email and notify the recipient.
Due to the accuracy of the spam validation process there is a very low rate of false positive detection, minimising the day-to-day administration of the service. If desired, individual recipients may be permitted to manage their individual quarantined emails, releasing their own messages - but not those identified as being infected or dangerous. Reporting of quarantined items can be customised and a range of immediate mail alerts, daily domain reports and reports to individual recipients can be configured.
ImerjaMail uses AV products from two vendors to scan all messages and attachments. The AV databases are updated hourly to constantly maintain the latest signature file from the respective vendors. In addition to this URLs contained within the email are checked against public databases of known phishing addresses.
An easy to configure management interface lets the domain Administrator select which attachment file types should be blocked, for both inbound and outbound communication. File detection is based on the extension name and the actual lead-in part of the file; it is not possible to evade defined protections by renaming a file, nor by hiding it inside a ZIP file. The system can identify over 40 of the most common file types and can be configured to default-deny or default-accept any new or proprietary file formats.
Inbound emails that pass all the validation checks are put in an output queue for delivery to the recipient. If the recipients email system is unavailable then ImerjaMail will continue to attempt to deliver the email for a minimum of 5 days before returning an undeliverable message to the sender. This minimum is increased for inbound email for our customers.
Imerja Security Operations Centre monitors all aspects of the system’s hardware and software components to detect and take corrective action so that the systems are always active and always up-to-date.
A "fair use" policy of 1000 messages (in + out) per user (mailbox) per month, averaged over the domain during a three months period is applied.