Managing nuisance email

This website provides help for UCAR staff who receive spam and viruses (malware) via email. For experienced users: Log in to the Mailguard system.

All email sent to "" addresses is scanned for malicious software (malware) before being delivered to recipients. Email that contains known malware is quarantined and scheduled for deletion.

To control spam, UCAR users can block it with two methods. The first method is blocklist filtering. You can set it up in less than five minutes, and it requires no maintenance. Blocklist filtering provides sufficient spam control for many people.

Content filtering is the second way UCAR users can block spam. It takes many minutes to understand and set up, and it requires ongoing maintenance, but it can intercept spam that is missed by blocklist filtering.

The following instructions and links give you good control over unsolicited messages that interfere with your email.

Controlling malicious software

Two anti-virus programs run on the UCAR email server and monitor incoming email for known malware. When malware is identified, it is deleted and the email message that carried it is automatically quarantined. During this time, the recipient can view the message. Then the system automatically deletes the quarantined message after 10 days have elapsed.

You do not need to take any action to deal with malware in your email. If you want to view your quarantined email, however, you must set up your Mailguard account. This is the same setup procedure that you use to enable email content filtering (described below).

Controlling unsolicited email

You must take action to control the spam you receive because no spam blocking is performed by default.

Blocklist filtering is very easy to implement. You can choose from two levels of blocking or you can turn it off.
How to set up blocklist filtering

In addition, you may also use the content filtering provided by the Mailguard system on the UCAR email server. This option requires more of your time and attention, but certainly less than that demanded by persistent spam. And as you help Mailguard learn to identify spam, less and less of your time and attention will be needed. You will need to continue monitoring your spam quarantine, however, to ensure that no genuine email is blocked.
How to set up content filtering

If you don't activate spam blocking

If you have never set up either type of spam blocking, then all email sent to your UCAR email account will be delivered except for email that contains known malware. The Mailguard system immediately quarantines known malware.

The Mailguard system notifies you once per week of any email that it intercepts. So even though you haven't enabled spam blocking, some of your email can still be blocked, and you may receive a notice that some of your email has been quarantined. This notice can be puzzling, so an explanation of the process is provided at Users with no spam blocking can receive Mailguard notice.

More information about Mailguard

If you enable content filtering, it is useful to read the Mailguard user guide for the malware and spam control system running on the UCAR email server.

To learn about Mailguard's features and tools, see the Mailguard system overview.

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