Our Organization email system

Warning: depending on your personal settings, our email system may delete some of your mail!

In our efforts to fight spam and viruses, many checks are performed on clients attempting to send mail to recipients hosted on our servers. Some of these checks are performed prior to the client actually sending the body of the message. Approximately 70% of the clients that attempt to send us mail are met with rejection. If the sender and the client are legitimate, but the connection attempt was rejected, the sender should receive notification from their server that their mail was rejected.
They would need to contact 'postmaster at domain.tld' to have the situation remedied.

Mail that passes the initial checks and is received by the Our Organization mail system may be stored in two or three different places. When our virus scanner detects a message containing a virus, that message is not delivered to recipients. Only the postmaster is notified of its existence. All viruses are quarantined, then deleted after 14 days. Messages with certain types of attachments are blocked by our system (executable files for example). When this type of attachment is detected, the message is quarantined to your MailZu account. You are notified when message with a banned attachment is found. Use the MailZu interface to request release of the message if you are confident the message is legitimate and does not carry a virus. Note that virus detection systems are not perfect so it is likely you will receive banned files that contain undetected viruses. Use your head, never open questionable attachments - even when they appear to come from from someone you know.
Contact 'postmaster at domain.tld' if you have special requirements regarding banned files.

You have control over what happens to spam. To change your settings you would log into the SquirrelMail webmail interface and click on the Options link near the top of the page, then the SpamAssassin Configuration link. You can Whitelist or Blacklist chosen senders and change spam settings. Avoid placing an excessive number of entries in your white/black list. Read that page to gain some understanding of the settings. Depending on settings, spam may be delivered to one of three places:
  • the INBOX
  • the Spam folder (a sub-folder of the INBOX)
  • the MailZu quarantine

    The MailZu quarantine is only accessible via our MailZu web page. This is separate from your webmail account. The items stored in your webmail account are also available from most any mail client (MUA) and may be accessed via the IMAP protocol (preferable) or the POP3 protocol. Examples of MUAs (Mail User Agents) are Microsoft Outlook Express and Mozilla Thunderbird. When accessed via IMAP, the mail stays on our system and therefore can be accessed from multiple IMAP clients (the webmail interface is also an IMAP client). However, there is a limit to how much mail can be stored on our system so pay attention to your quota (percent of quota used is displayed in the upper left corner of the webmail page). Remember to delete messages you no longer need and to purge your trash. If using a remote IMAP client (as opposed to the web interface) you can also move messages off our system and onto yours by moving them to a local folder. Any mail older than 24 days is automatically removed from your Spam folder. If you need messages from there, move them to a different folder.

    If using the POP3 protocol, when you connect to our server, mail is transferred from our server to your computer and then deleted from our server (provided you have not chosen to "keep messages on server", which of course is not recommended due to the fact that you will soon reach your quota). The POP3 client can only retrieve mail from the INBOX and knows nothing about messages in other folders. This concept is important to understand because it will affect how you configure your SpamAssassin settings.

    SpamAssassin is used to assign a 'spaminess' score to the majority of messages. The SpamAssassin developers use 5.0 as the target score that divides spam and non-spam. One must realize that even though they strive to score non-spam less than 5.0 and spam greater than 5.0, it is difficult to do so. Spammers work very hard to get their spam to score low and legitimate mail can (and will) occasionally score higher than 5.0. It's actually less work on your part to set this threshold a little higher and allow some spam into your INBOX. Doing so means you will have less legitimate mail in your Spam folder (or quarantine) and therefore will have more confidence in discarding it. If you set your threshold low you will have more legitimate mail in your Spam folder (or quarantine) and will spend more time scrutinizing it due to lack of confidence. Here are some addition details of the particular settings:
    Policy Tag2 Level Kill Level Cutoff Level Notes
    Quarantine, discard high score spam 5 8 14 This would work well for an IMAP client but would be less suitable for a POP3 client. The tag2 level is set rather low - this keeps the INBOX fairly clean of spam. Mail that scores between 5 and 8 ends up in the Spam folder. Only a small sample of the total amount of spam sent to you should end up in the Spam folder. Spam scoring at 8 and above is directed to the MailZu quarantine and may on occasion contain legitimate mail. It is not unusual for promotional mail from valid sources (that you may have subscribed to) to score in this range. Legitimate companies allow you to unsubscribe from their mailing lists. Anything over 14 is discarded. Any time mail is discarded there is a potential for loss of legitimate mail, but at a score of 14, that chance should be reasonably low.
    No spam goes to quarantine 6 14 14 In this case messages either go to your INBOX or the Spam folder. All messages that score at 14 or over are permanently discarded. The MailZu quarantine still receives messages with banned contents (as always).
    Default - all spam to spam folder 6.5 9999   This is the default policy. Any message that scores at 6.5 or over will be placed in the Spam folder. Mail left in the Spam folder over 24 days is deleted - please move items you wish to keep to another folder. If using a POP3 client to retrieve mail you will need to use the webmail interface to access the Spam folder (which is essentially acting as a quarantine area in this case).
    All spam to quarantine 8 8   Any spam that scores at 8.0 or greater is sent to the MailZu quarantine. Remember that spam sent to MailZu is deleted after 24 days.
    Permissive, no spam quarantine 9 20 20 Same as "No spam goes to quarantine" but more permissive.
    Permissive, with spam quarantine 10 10 25 No spam is sent to Spam folder (which is desired if using a POP3 client) but messages that score at 10 or above (and less than 25) are quarantined to the MailZu quarantine. Messages that score over 25 are discarded.
    Nothing goes to spam folder 15 15 15 This would be especially useful for a POP3 client who does not desire to use the webmail interface. No spam would be sent to the MailZu interface either. The MailZu interface would still be used as a quarantine for messages containing banned attachments however. While a level of 15 seems high remember that many mail clients offer the ability to filter mail using the contents of mail headers. The filtered mail can then be routed to a folder, such as a Spam folder. For example, in Thunderbird it is possible to create a custom filter that looks for a X-Spam-Level header that starts with ****** (6 stars - six points). Unfortunately Outlook Express does not offer the creation of custom filters based on arbitrary header fields.
    Do not tag or block spam 9999 9999   All messages (that are not blocked due to virus or banned contents) should be received in your INBOX.
    Custom ? ? ? Now that you understand the concepts, you decide what is best for you.


    An additional item to consider: spam messages sent from our own local domain(s) will ignore your personal preferences and could either be passed to you (unlikely), or (more likely) quarantined to MailZu. This means that regardless of your settings, you may still have mail in the MailZu web page.