CitrusMail - How it works

Put simply, CitrusMail collects inbound email, analyses it, filters it, passes the clean messages on to you while logging the result. In more detail the steps break down as follows:

Mail Collection

CitrusMail can receive email using SMTP, POP3 and IMAP.

The ideal option is SMTP as messages are received instantaneously and contain much more information on which to perform analysis. This requires that the MX (Mail eXchanger) records within the DNS for your domain need to point to CitrusMail. Our experienced engineers will provide whatever help is necessary to aid with this change.

If SMTP is not an option or you are consolidating multiple legacy mail systems, perhaps migrating from mailboxes hosted with several ISPs, CitrusMail can collect messages from one or more remote systems. This option can be applied either for an entire domain (often called multi-drop POP mailboxes) or for individual recipients.

Both of these options can be used in conjunction so that email can be received via a combination of SMTP or POP and passed through a common filtering policy before being delivered to your internal mail server.

Message analysis and filtering

When an incoming connection is received by CitrusMail it is subject to a multi-layered scanning process in accordance with the configuration that has been set for the intended recipients of the message.

The message is checked with three separate anti-virus engines in parallel, our proprietary spam detection system which incorporates advanced spam countermeasures and bayesian analysis and then against three separate decoders to identify attachments by name and actual type; the latter prevents the sender from simply renaming a banned file to have a different file extension.

The modules which make up the scanning engine even analyse the SMTP and underlying TCP protocols used in delivering the message.

At each stage flagged messages can be handled in a number of ways including being discarded, quarantined, redirected or tagged such that your local systems can take appropriate action.

Mail delivery

Finally, clean email is forwarded on to you, either by SMTP to the your internal mail server or to a POP3 mailbox on the CitrusMail platform.

Where the SMS notification extension is configured for the recipient a customisable text message can be sent to one or more mobile phones to alert you of the message's arrival.

Message logging

Every email that is presented to your CitrusMail service is logged.

The last 60 days logs can be searched in real time through the extranet and complete logs from the start of your service can be downloaded as comma separated variable files, suitable for analysing with a spreadsheet or database package.

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