|
In October 2006, spam levels worldwide reached new record highs due to
adoption of new spammer techniques. These new levels did not
subside; they
have become the new normal spam levels. Spam is now estimated to compose
approximately 85 percent of all e-mail traffic. The University of
Maryland's e-mail infrastructure is under increasing stress from these new
levels.
On March 3, 2007, Office of Information Technology (OIT) implemented new
e-mail forwarding servers to provide
some relief from the spam plagues. These servers are not only
faster but also run the
Mirapoint
MailHurdle software for increased spam protection. Any e-mail address
ending in "@umd.edu" will be affected by this new spam protection
software.
While no system can guarantee the elimination of all spam, the university
should see a decrease in the amount of spam entering the UMCP e-mail
servers through the use of this software.
MailHurdle records three pieces of information (called a "triplet")
about any particular mail delivery attempt and consists of the following:
- The IP address of the host attempting the delivery
- The sender address
- The recipient address
MailHurdle's approach to blocking spam and viruses is to check this
"triplet." If UMCP's MailHurdle servers have never encountered
this triplet, they will delay the message with a temporary failure.
While legitimate sending servers automatically retry messages on temporary
failures, spammers rarely do. If the MailHurdle servers receive mail with
that triplet again within a certain period of time, they will begin accepting
messages from that triplet and will continue to accept e-mail from that
triplet for a month. Every time a message from that
triplet arrives, the acceptance period is extended for another month from
that arrival.
Anyone who uses an "@umd.edu" e-mail address will notice some
differences in e-mail delivery with this new software. Specifically, the
first time that a message is sent to you from a new sender that is outside
the "umd.edu" domain, you will experience a delay in the delivery. The
delay is dependent upon the sending server's retry delay and could last from
a few minutes to an hour or more. After that first message is delivered,
messages from that sender will be delivered normally until you have a gap
of over a month between messages. If there is a gap greater than a month,
the first message after the gap will be subject to the initial delay. All
mail from UMD domain addresses (anything ending in "umd.edu") is,
however, exempt from this delaying tactic.
Mirapoint has integrated MailHurdle with its existing allow/deny lists and
unsolicited commercial e-mail (UCE) blocking. Therefore, if a message
sender or domain
is already allow-listed or deny-listed, MailHurdle is not applied.
Tips to Remember about MailHurdle
- Have your colleagues outside the University of Maryland send you a test
message. That will start the automatic month-long permission of
that e-mail address and IP address.
- Every time that your colleague then sends you another message, the
month-long permission renews for another month.
- Make sure that new senders allow at least 5 minutes to pass before
they send a second message to you.
- It is possible to receive a second message from a new sender before the
first one arrives. The first message is delayed for several minutes
while the second message is delivered without delay.
|
