Mail
Your e-mail address is <username>@cita.utoronto.ca.
Email is received, presented and sent by the CITA mailserver running on
our central fileserver (quail). This is an IMAP server which lets
you
access your personal inbox (and folders) from any properly-configured
machine (at home or at CITA).
Everybody's inbox resides on the central mail server and can be
accessed as /var/spool/mail/<username>.
Because this mail space is shared, you should ensure that you
periodically clean your inbox. Common practice is to use your email
client to sort and move your
email into folders which reside in your home directory (and will still
be visible if you connect from outside CITA).
You have a number of choices for an email client (the software which
lets you read and compose email). The most commonly used at CITA are pine, thunderbird and mozilla mail. Pine is a
text-based viewer which just requires that you have a local
window/terminal that is logged into a CITA machine. Thunderbird
is the default GUI-client in Fedora and exists on all the Linux
workstations (and can be easily installed on your home windows or Linux
box).
CITA Mailing Lists
& Addresses
There are a number of mailing lists. Send email to one of these and
it will be received by the entire group of people. All lists are
defined in /cita/share/mail/aliases and their recipients are listed in files in that
same directory.
- citalocal - despite the name this
goes to all local people (faculty, staff, postdocs) AND most others
with accounts at CITA
- citaprof - all the faculty at
CITA
- citapostdoc - all the CITA postdocs
- citastaff - all CITA staff (office staff and sysadmin staff)
- citavisitors - visitor accounts as well as long-term visitors
- citagrad - all CITA grad students
- citafloor - everybody in citaprof, citapostdoc, citastaff, citavisitors, and citagrad
- citamckenzie -everybody with an account on the McKenzie cluster
- citasummer -all the CITA summer students
- requests -system admins and
local experts
Margaret and Candace can be reached as "citadmin'' and "office'',
respectively. The logins (email addresses) of all current
CITAzens can be viewed in the directory
listing on the CITA website. You can also use the finger
command to locate information about people by first, last or login
name; e.g. finger chris,
or finger loken, or finger cloken.
Configuring
Thunderbird/Mozilla
The critical settings for Thunderbird can be found under the "Edit"
tab in "Account
Settings" ("Mail & Newsgroup Account Settings" if using Mozilla).
The incoming server name should be mailbox.cita.utoronto.ca.
The server type is IMAP and you need to check ``Use secure connection
(SSL)'' (then the connection will automatically be made over port 993).
The outgoing (SMTP) server name is the same as the incoming server
name if you are on the CITA network (the "use name and password" box on the "SMTP server"
page should NOT be checked). At home you will need to use the
SMTP server provided by your ISP (for sympatico users this is likely
smtp1.sympatico.ca). In either case, do not use SSL for this
outgoing connection.
You should also ensure that you are NOT composing messages in HTML
format (under ``Composition and Addressing'').
When you connect to the CITA mailserver, you will likely get warning
messages about security certificates. Just choose to permanently accept
the certificate and click OK if it keeps bugging you. Then you should
be asked to login with your regular cita username and password.
Spam-Filtering:
SpamAssassin is being used to tag potential spam based on the number of
"hits"
or points it receives - the more hits, the more likely that the message
in question is spam. If
the number of hits exceeds a threshold (now set at 5.0), then ``[SPAM]"
will
be appended to the beginning of the subject line and the header
``X-Spam-Flag: YES" will be added (plus details on the
number of hits it scored etc).
By default, nothing else happens to your spam except for this tagging.
However, you can choose to automatically move spam to its own
folder (i.e. get it out of your inbox) by creating and editing a .procmailrc file in your home
directory or by appropriate configuration of your email client.
The first method is probably easiest (if you use the second method you
have to separately configure your home and CITA browsers and redo the
configuration if you change or reinstall your client).
Tips on configuring your email client to filter spam (the second
method) can be found on the spam
page on the Astronomy web server. Here we consider just the
preferred, first method. Create a file called .procmailrc in your home directory
with the following lines (this assumes you have a folder in your home
directory called mail):
# the following
block stores all potential spam in ~/mail/spamdel
:0:
* ^X-Spam-Flag: YES
/${HOME}/mail/spamdel
Now mail tagged as spam will be automatically
moved into the spamdel folder. Remember to configure your email
client so that it can access the spamdel folder (so you can check
what's in there).
NB - there may be false
positives so check your spam folder periodically!! And delete it
when it gets large!
Training SpamAssassin's Bayes Filter:
The best way to maximize the effectiveness of SpamAssassin is to periodically train it with your own email. However, you must be
very careful with this procedure because you could easily teach your filter to reject legitimate email and accept spam. Users who
take this approach are on their own and are responsible for monitoring that their email is OK!
The basic procedure is to collect your own, hand-checked samples of "spam" (real spam that was NOT tagged as spam by SpamAssassin) and
"ham" (legitimate email) and then run sa-learn to update your personal Bayes database. Note that each sample must have at least 200 emails,
you must train with both types of email and, very importantly, they must be hand-checked (any spam in the ham folder, or vice-versa, can cause
unexpected behaviour of the filters).
- check the current status of your Bayes database with, e.g. sa-learn --dump magic
- save your untagged spam in its own mail folder (e.g. ~<user>/mail/untagged-spam)
- save your legitimate email (or a representative portion) in a separate folder (e.g. ~<user>/mail/legit)
- train your filter with both collections of email:
sa-learn --spam --mbox --progress ~/mail/untagged-spam
sa-learn --ham --mbox --progress ~/mail/legit
- repeat the check in the first line; the nspam and nham counts should have increased as expected
- monitor your inbox and your folder that contains the spam identified by SpamAssassin until you are sure the training has not resulted in any problems
- continue to collect spam and ham and repeat the sa-learn commands whenever you notice an increase in the percentage of spam slipping through your filters (monthly?)
Some tips:
- the filter can potentially learn and add info to your bayes database every time you run sa-learn so you can do this repeatedly (and with smaller smaples of spam & ham)
though the filter will only add info corresponding to emails that it has not seen before
- if your database is corrupt you could use the --clear option with sa-learn to wipe your database and then repopulate it
- your "legit" sample could consist of the various mail folders that you maintain (run the sa-learn line for each folder in turn). Just make sure they do not
contain real spam
- it's probably best to use the default value of "required_hits" (i.e. 5) in your ~<user>/.spamassassin/user_prefs file (there are lots of other default
values under the hood so changing required_hits could have unexpected consequences)
- it might be useful to boost the score (3.5 by default) given to an email that has been judged spam at the 99% level by the Bayes test so that it will
definitely be tagged as spam (the default value of "required_hits" is 5.0). Add the following line to your user_prefs file:
score BAYES_99 0 0 5.0 5.0
- read the man pages; man sa-learn
E-mail tricks:
Procmail is a powerful scripting program that we use on our mail
server.
To use it, make a .procmailrc file in your home directory. For
examples
and instructions on how to write some nifty procmail scripts, consult
the
procmailex man page by typing "
man procmailex".
Spam filtering
Using procmail, you can filter your spam into a different mail folder
upon
its delivery. This means that if you use several different
programs
to access your mail, they will all see the same inbox, even if they
don't
have spam filtering turned on.
To do so, copy and paste the following into your ~/.procmailrc file:
# the following
block stores all potential spam in ~/mail/spamdel
:0:
* ^X-Spam-Flag: YES
/${HOME}/mail/spamdel
E-mail forwarding
Want to forward your legitimate (non-spam) e-mail to
some other address? Add this to your ~/.procmailrc after the
above lines:
#use :0c to keep a
copy of the message on the server
#:0c
# OR use :0 to simply forward the message
:0
#remove this line to remove spam filtering:
* !^X-Spam-Flag: YES
#space separated list of addresses to forward
to (list must start with!)
! username@somewherethatsnotcita.com username@anotherplace.com
Note that this forwards your email but does not keep a copy on the CITA
mail server. If you comment out the ``:0" and uncomment the ``:0c" then
all your email will stay in your inbox
and a copy will be sent to the
address(es) in the final line.
Automatic vacation response
To have a response automatically sent out telling
people that you're on vacation, copy and paste this into your
~/.procmailrc (remember to
replace <username> with your actual
username). Also, it would be useful to place the spam filter rules
in your .procmailrc to filter your e-mail. Make sure the spam
filter rules are before e-mail forwarding rules.
# Response to message while on vacation
:0c
| /usr/bin/vacation <username>
And write out a response in your ~/.vacation.msg file that looks
something like this:
Subject: away from
my mail
I will not be reading my mail for a while.
Your mail concerning "$SUBJECT"
will be read when I'm back.
Only one response per email address is sent; the email addresses accumulate in ~/.vacation.db. So next time you turn the automatic response back on, remember to delete that file (so that people get the message again).
Separating your mail into different folders
Say you are subscribed to a mailing list all about the TV show Three's
Company
whose address is threescompany@mailer.com. To automatically move
all this email into its own folder you would put the following into
your ~/.procmailrc:
# the following
block stores all threescopmany@mailer.com's mail in ~/threescompany
:0:
* ^From.*threescompany
/${HOME}/threescompany