/admin/spam system
part of the ArsDigita Community System
by Philip Greenspun
The Big Picture
This is a module to be used only by the publisher. Moreover, it has
very little user interface of its own: URLs underneath /admin/spam are
typically only invoked from within /admin/users. The data model is in
/doc/sql/spam.sql.
Under the Hood
- we keep a history of all the spam we've sent to users in the
spam_history table
- forms that allow a publisher to spam (e.g.,
/admin/users/action-choose.tcl) generate a new spam_id for the blank
form; this way a double click does not result in a spam being sent twice
(spam is bad enough!)
- The spam sending system tries to send email using each users email_type preference
(from the users_preferences table). You can enter copies of the spam mail message
formatted as plain-text, HTML, and AOL-HTML (some HTML subset). The spam sending routine
will attempt to send the proper format to each user based on their preference. The default
is plain text.
Sending spam from the browser
The /admin/spam page has a link
to send a plain spam message to a class of users, or to send a
combined plain and HTML message. In both cases you will be given a
form which asks for a subject line, a target class of users, and a
date to send the message. The from-address will probably be overridden
with a machine-generated email address in order to make the automated bounce
handling scripts work.
General Tcl Substitution in Message Body and Subject Line
The spam entry forms all have a checkbox labeled Template?.
If checked, then Tcl evaluator will be run at the time the message
is actually sent on message subject and body, substituting
variables or procedure calls wherever \$ and \[\] chars are
found. This is specially useful for creating automatically generated
templates, such as a daily report which runs a tcl procedure to query
the database or create some other summary message.
Note: if you have the Template? option selected, make sure you
use backslash to quote any $ or '[]' characters in your message, if you do
not want them to undergo evaluation by the Tcl parser.
Guessing user's email preferences
In the site .ini file, you can set up a list of patterns to be used to
guess the email type preference of new users, based on their email address.
The param is an association-list, with SQL patterns on the left, and
pseudo-mime types on the right. Supported types right now are text/html,
text/html, and text/aol-html.
EmailTypes={%@hotmail.com text/html} {%@aol.com text/aol-html}
Manually Sending Spam From a File on the Server
You can schedule a spam which gets its content from files in the file system,
using the "Post spam from file" link on the admin spam page. It will look
n the "Drop Zone" directory (described below) for files with the specified names, and
send the spam using them as the content to the target user class of your choice.
Spam Which Is Sent Automatically: Newsletter Groups
The spam daemon can send out daily (or any period you want) email to
groups of users in designated user classes. There is a configurable list of "daily spam"
files, accessible from the /admin/spam page via the
"View/modify automatic daily spam file settings " link.
Every time you create a new user group, a new user_class will be created to
go along with it. You may want to designate a specific group type to be the "Newsletter"
group type, and then you can make a user self-service subscriptions page, which simply
adds or removes the user from the groups of type Newsletter. You can then configure
the Daily Spam Locations admin page to look for content files which correspond to
the different Newsletter groups. Here is an example of what the admin page
might look like for sending three types of newsletters; Daily, Weekly, and Special Updates.
You can enter the following information for an automatic spam daily message:
- User Class
- (pulldown menu)
- Subject
- Note that you can include the current date in the subject line of
the spam, by including the string "%%DATE%%" in the subject.
- File Prefix
- The filename prefix where you will deposit the new content for periodic mailings.
Drop Zone Directory
The files should be placed in the "Drop Zone" directory specified by the .ini
parameter DailySpamDirectory:
Example:
DailySpamDirectory=/home/johnny/spam
For each spam defined in the Daily Spam list, the system will look for
the following files:
file_prefix-MM-DD-YYYY
file_prefix
Note: Be sure to always use two-digits for Month and Day fields, i.e.,
03-06-1999. Don't forget the leading zeros.
If a file whose name matches with the specified prefix and the current
day's date is found, the contents are queued up to be sent as spam to
the designated target user class.
The spam system will only send a dated spam once. It keeps a history of
all spams sent, and will be robust across server restarts. If the server
is restarted in the middle of sending a spam, the spam daemon will resume
sending where it left off in the list of users.
Be very careful with filenames that have no date suffix!
If you use a filename with no date suffix, the spam will be sent once a day
from the file. This behavior is designed to support a special case spam
for new users, where the user class contains a magic query like
select user_id from users where trunc(registration_date)=trunc(sysdate-1)
which is carefully constructed to always select a mutually exclusive set of users each day, and never repeat the same user twice.
HTML and AOL content types
Some users will have designated preferred MIME types for email via the
users_preferences table. Currently we support HTML and AOL types in addition
to plain text. If you create auxiliary files with the names
file_prefix-html-MM-DD-YYYY
file_prefix-aol-MM-DD-YYYY
Then content from these files will be sent preferentially to users who have
their email types preferences set in the database.
Setting the .ini Parameters
Here is a summary of the .ini params you will need
[ns/server/yourserver/acs/spam]
; Pairs of {email_addr_pattern pseudo-mime-type}
EmailTypes={%@hotmail.com text/html} {%@aol.com text/aol-html}
DailySpamDirectory=/web/yourserver/spam
SpamRobotFromAddress=email-robot@yourdomain.com
BulkMail
By default the spam system uses the built-in
AOLserver ns_sendmail routine. This is adequate for low volume
mailings, but if you need to send mail to more than about 500 users,
then it has serious limitations. A high-performance module called
bulkmail which has a multi-threaded mail client which can talk
to multiple mail servers concurrently, and can generate the QMAIL
style VERP return addresseses to make automatic bounce handling
possible. This will soon be available as part of the core ACS
distribution, and the spam module will have an option to use this as
the mail transport rather than sendmail.
For more info on the configuration of bulkmail and qmail, see bulkmail and qmail configuration
philg@mit.edu
hqm@arsdigita.com