Firstly though, here’s what is going on with\u00a0incoming email:<\/p>\n
ON ARRIVAL AT THE UNIVERSITY<\/strong><\/span> OXMAIL then sends messages on to their destination, which might be Nexus, forwarded to a personal email address outside the University, or to a departmental server.<\/p>\n ON ARRIVAL AT NEXUS<\/strong><\/span> Nexus is able to automatically move spam messages into the Junk folder of your mailbox before you see them, but only if you tell\u00a0it to do so<\/em>. This is a two-stage<\/span> process:<\/p>\n WHY DO YOU TELL US TO TURN OFF JUNK FILTERS IN OUTLOOK?<\/strong> <\/span>(or other email clients?)<\/p>\n The assessment of spamminess done by OXMAIL is logged, consistent, and repeatable. If two people are sent the same message, and have the same spam-filtering preference set, then the same thing should happen to that message for both people.<\/p>\n End-users’ applications aren’t so clear-cut. Each program can use widely differing technologies to assess spam and the software which scans it isn’t always the same version,\u00a0even when the application is the same. Furthermore,\u00a0messages that are moved to Junk by the email client application can’t be differentiated between a user choosing to move a message between folders or their software doing it for them. All that Nexus’ servers see is an end-user request for a message to be moved.<\/p>\n In other words Outlook, and others, can do a pretty good job of spotting and filtering spam after it’s delivered. But we can’t guarantee that your program\u00a0won’t falsely-identify a genuine message as spam. We can’t guarantee that your experience will match that of the person next to you (do they update as often as you do?). We can’t see in our logs what process decided to move that message between folders.<\/p>\n By deactivating client-side spam filtering we can be sure that the only\u00a0spam processing that does happen is recorded in message headers.\u00a0 This gives us a fighting chance of diagnosing any issues with the process. If you do spam filtering in your application you are muddying the waters for us if things misbehave and you want us to help you to troubleshoot.<\/p>\n WHAT CAN I DO BEFORE LOGGING A TICKET?<\/strong><\/span><\/p>\n <\/p>\n EDIT 1st August 2016:<\/p>\n In the case of a shared mailbox SelfReg does not currently allow you to alter the spam preference – it is limited to the currently-logged-on user. However the Nexus team can manually apply spam preference\u00a0values for you if spam becomes an issue within a shared mailbox.<\/p>\n","protected":false},"excerpt":{"rendered":" We have had a spate of spam making it into Nexus mailboxes recently, provoking a flurry of discourse on the ITSS-Discuss mailing list. To be able to stop spam more effectively there are some checks that IT Support Staff can … Continue reading
\nNew messages arrive at OXMAIL and are scanned. Details of Oxmail’s processes can be found here:\u00a0http:\/\/help.it.ox.ac.uk\/email\/scanning\/index<\/a> and here:\u00a0https:\/\/help.it.ox.ac.uk\/network\/smtp\/relay\/index<\/a><\/p>\n
\nThe spam score assigned by OXMAIL is translated directly into a Spam Confidence Level, or SCL. Each asterisk in the\u00a0X-Oxmail-Spam-Level<\/strong> header\u00a0is counted: the total becomes that message’s SCL. So this example ‘X-Oxmail-Spam-Level: *********’ would have\u00a0an SCL of 9.<\/p>\n\n
\nThe higher the SCL is that you can accept, the fewer messages will be moved into Junk. The options equate to the following:
\nOFF: All messages will go into your Inbox.
\nLOW: Messages with an SCL above 7 will be moved to Junk.
\nMEDIUM: Messages with an SCL above 5 will be moved to Junk.
\nHIGH: Messages with an SCL above 3 will be moved to Junk.<\/li>\n<\/ol>\n\n
![\"nexus_itss_spam-processing[1]\"](\"http:\/\/blogs-new.it.ox.ac.uk\/nexus\/files\/2016\/07\/nexus_itss_spam-processing1.jpg\")
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