Electronic Mail at CAL

Each user account in the CAL network has a mailbox, initially configured with 1GB of storage, which is accessible mainly through IMAP with TLS/SSL. You can categorize your e-mail into subfolders within this mailbox. A webmail interface (secured via HTTPS) provides an alternative access method. The mail is filtered for spam and viral content before delivery.

IMAP, SMTP, and Webmail

Internet Message Access Protocol (IMAP) is a system by which your e-mail is kept on the server and can be accessed from any machine on the network. When you want to view, send or manage your messages, your e-mail program (client) connects to the CAL central e-mail server for access. Because your e-mail always remains on the server, you can easily retrieve it from virtually any location with Internet access. IMAP is useful if you travel frequently, access your e-mail at multiple locations, and/or use web mail as your main mail client.

Recommended Mail User Agents (Email clients)

You can access your mail through a variety of different IMAP clients. Some that we recommend are:

  • Thunderbird
  • Evolution
  • netscape7 (on sun network)
  • Mutt (text based)

Configuring Your Email Client

Detailed information regarding the email server settings and related information can be found on the MUA Configuration page.

Using Web Mail

Web mail is an alternative to accessing your email via an email client. It can be used at any time but is particularly useful when travelling. Simply point your browser to https://mail.astro.columbia.edu/ and log in.

  • when using webmail, please note that the session will disconnected after a certain period of inactivity. This is usually around 10-15 minutes after being logged in to the webmail interface without clicking any buttons or performing any actions. To avoid this, force webmail to auto-refresh the side navigation bar every 5 minutes. To do this, log in to webmail, click on “Options” and then “Folder Preferences”. You will see an option titled “Auto Refresh Folder List:”. It is defaulted to Never. Change the setting to 5 minutes and Submit the changes.
  • please note, users have complained of multiple email messages being sent when using the Back button on browsers, this is true when using Safari 2.0.4 (from 2005) but this may also be the case when using other browsers.

Managing Your Incoming Mail

E-mail Quotas

There is a 1GB storage limit for every CAL e-mail account. Your IMAP quota is visible from any IMAP client which supports the QUOTA capability (and most do). It can also be seen from the CAL webmail site. To view your quota in Thunderbird 1.5, for example, select the inbox of your CAL account in the "Folders" pane, and choose Edit|Folder Properties... from the menu. The Quota tab in the dialog box that appears shows your quota.

It is important to keep in mind that you have a limited amount of space on your CAL email account to store email. As mail addressed to your account comes in, it is placed in your Inbox mailbox, and it will stay there indefinitely, until you move it to your personal computer or delete it. When the total amount of email you have in your Inbox exceeds your account's Inbox allotment, new incoming email will be bounced. (Returned to its sender.) Each account has a reasonably large allotment, but if you get a a few -- or even one -- email messages with large attachments, your Inbox can fill up pretty quickly. You will receive a series of automated messages as the size of your Inbox approaches your Inbox quota.

E-mail quota extensions

We will try to accomodate reasonable requests for quota extensions. Requests for a moderate increase over the existing standard quota levels, along with a reasonable, clear explanation of the extenuating circumstances leading to the request will be prioritized.

Spam Filtering

CAL is running DSPAM to provide users with personalized spam filters that will adapt to your preferences. Mail messages determined by a user's filter to be spam will by default be routed into the user's spam subfolder (based on the X-DSPAM-* headers added by DSPAM).

If you find a non-spam message in your spam folder, you should tell the filter that it made a mistake. You can do that by simply putting another copy of the message into the not-spam subfolder of your inbox (you may need to "subscribe" to that folder to make it visible).

Conversely, if you find a spam message in your inbox, you can retrain your filter by moving it to the missed-spam subfolder.

Mail left in either missed-spam or not-spam will be removed by the filter once it has been properly retrained. If you conscientiously retrain your filter when it errs, it will be better able to anticipate your preferences in the future.

Personalized Filtering and Forwarding Email

Traditional UNIX-style .forward files are not used on the new CAL system. We're using sieve, an emerging standard for mail filtering. You can see an example sieve script here (this example script is installed by default for all CAL users, and can be found on Configured Workstations at /usr/share/doc/cal-base/examples/sieve/cal-default.script. It filters spam into the user's spam subfolder based on the X-DSPAM headers mentioned above).

If you want to write a new sieve script, simply put it in a text file on a Configured Workstation, and use sieveshell to import it to mail.astro.columbia.edu. For example, here is dkg importing a sieve script located at ~/newsieve.script (note that you will probably have to type kinit first to create your kerberos credential):

[0 dkg@kalyke ~]$ sieveshell mail
connecting to mail
> put newsieve.script 
> activate newsieve        
> quit
[0 dkg@kalyke ~]$ 

You may also be interested in some Sieve Examples for CAL.

If you have trouble with sieveshell connecting to the mail server, make sure you have a valid Kerberos Credentials Cache.

Message size limit and handling large attachments

There is a 50MB message size limit; see ticket #242 for a discussion about that. Attachments are base64 encoded which expands them by a factor of 4/3. Big email messages are generally a bad idea and poor use of bandwidth. Instead, CAL suggests that you put large files you'd otherwise attach to e-mails on your personal website in ~/www/files/ (or something like that) on the filesystem side, and then just send the other person a link to that, http://www.astro.columbia.edu/~USERNAME/files/ . If you put an 'index.html' file in your ~/www/ directory, the subdirectories under that (e.g., ~/www/files/) will be hidden from random Internet users (and search engines).

For other ways to transfer large amounts of data see Transferring Large Data.

Email Lists

A listing of all the public mailing lists on mail.astro.columbia.edu can be found here. Click on a list name to get more information about the list, or to subscribe, unsubscribe, and change the preferences on your subscription.