Incoming e-mail filtering on mail server

Metropolia filters e-mail to fight off junk e-mail, viruses and malware. All filtering related checksups are done by the e-mail gateway before e-mail is allowed to pass through to the user.

Forbidden file formats

The following file formats are not accepted in:

• .pif
• .scr
• .exe
• .vbs
• .cpl

These files must be packeged e.g. in a zip packet.

Black lists

Metropolia does not accept in e-mail from black listed servers. Currently the following lists are used:

• sbl-xbl.spamhaus.org
• bl.spamcop.net

Greylisting

The so called greylisting technic is in use at Metropolia as a means of fighting off spam e-mail sent via botnets. Read more on the technic in the Ministry of Traffic and Communications' (liikenne- ja viestintäministeriö) junk e-mail package.

Antivirus policy

Incoming and outgoing e-mail is scanned for viruses. E-mail containing viruses are not accepted in.

Junk mail scanning

The contents of received e-mail is automatically analyzed with the SpamAssassin software. Based on the analysis, an estimate of the likelihood that the message is junk mail is added to the message title. The titles can be used in sorting junk mail into its own folder.

Titles of suspect messages are similar to the following:

X-Spam-Flag: YES
X-Spam-Score: 6.919
X-Spam-Level: ******
X-Spam-Status: Yes, score=6.919 tagged_above=-9999 required=5	tests=[HTML_MESSAGE=0.001, ...

In the above, the X-Spam-Flag title can be used for sorting junk mail. The X-Spam-status title tells how many points a message has received. A more detailed description of the criteria can be found on SpamAssassin's home page

Outlook Web App

Junk mail filtering instructions in the Outlook Web App browser interface can be found here.

Outlook 2010

Junk mail filtering instructions in Outlook 2010 can be found here. http://help.outlook.com/fi-FI/140/ms.exch.ecp.JunkEmailConfiguration.aspx?r=ia

Junk mail still comes through

Junk mail filtering is meant work so that appropriate messages are not filtered off. It is inevitable, though, that junk mail passes through filtering. If you receive a lot of junk mail, you can send samples to Helpdesk. We can try to make filtering more effective in such cases although we cannot give any guarantee.

The message must be forwarded as attachment so that header information is preserved.

In OWA this is done by clicking the message with right button and selecting "Forward as Attachment":

With Outlook 2010 choose "More" -> "Forward as Attachment":

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