Files that affect your mail

The default mail setup at Nevis works for most users. However, if you'd like finer control over your e-mail, mail notifications, mail forwarding, spam processing, mail filtering, or are trying to fix a mail problem, the following information can be useful.

In the descriptions below, $user is the name of your Nevis Linux cluster login account.

/a/mail/inbox/$user

This is the file that contains the contents of your INBOX. On the mail server, it's located in /mail/inbox/$user, but the above path makes the file visible on other the other systems on the cluster via automount.

/a/mail/folders/$user

This is the default location of your IMAP mail files. On the mail server, this path is /mail/folders/$user, but the above path makes the file visible on other the other systems on the cluster via automount.

/a/mail/folders/$user/.subscriptions

This file contains the list of IMAP folders that you see in your mail reader. For the most part, you don't have to change the contents of this file; you can drag, drop, create, (un)subscribe, etc., using your mail program. But every once in a while, it's easier to edit this text file than it is to manually click on lots of different folders.

/a/mail/forward/$user or ~/.forward

The forwarding file controls how your e-mail is forwarded, and can also be used to automatically send vacation messages.

There are two places where you can put your forwarding instructions: /a/mail/forward/$user or ~/.forward. The latter name is the standard location for a forwarding file, and it's supported at Nevis. The former location is preferred, however, since the file will remain available to the mail server if your home directory becomes unavailable; e.g., if your group's server goes down.

If you have both files /a/mail/forward/$user and ~/.forward, only the lines in the former will be interpreted. The latter will be ignored.

/a/mail/procmailrc/$user or ~/.procmailrc

Procmail is a program that delivers your mail to your INBOX. You can create a file /a/mail/procmailrc/$user or ~/.procmailrc file to filter messages, automatically direct mail into certain folders, and other advanced operations.

There are two places where you can put a procmail command file: /a/mail/procmailrc/$user or ~/.procmailrc. The latter name is the standard location for a procmail file, and it's supported at Nevis. The former location is preferred, however, since the file will remain available to the mail server if your home directory becomes unavailable; e.g., if your group's server goes down.

Many mail readers (such as Thunderbird) have similar facilities. The advantages of using procmail are:

• Procmail offers more flexibility than most mail readers. For example, most mail readers cannot send an e-mail in response to a particular message you receive; procmail can.

• Procmail runs on the mail server, which means it operates on your e-mail as it receives it. A mail reader can only process your messages as it reads them off the server. In particular, if you read mail using more than one computer or more than one mail-reading program, you might want to put your mail filtering in procmail instead of duplicating that functionality on different machines and programs.

The disadvantage is, of course, complexity; procmail uses its own command language.

If you're interested in exploring procmail, I recommend the following resources:

• Procmail FAQ and tips.
• The procmail man page.
• The procmailrc man page.
• The procmailex man page.
• WilliamSeligman's procmail file at /a/mail/procmailrc/seligman.

If you have both files /a/mail/procmailrc/$user and ~/.procmail, the commands in both will be executed. Be careful! This is not the behavior of the forwarding files described above!

~/.spamassassin/user_prefs

For the most part, you can ignore the contents of your ~/.spamassassin/ directory, which is automatically created for you the first time you receive mail at Nevis. The one file that you might want to look at is ~/.spamassassin/user_prefs, which allows you to control the functionality of SpamAssassin.

Your mail reader may also offer spam-filtering options. The advantages of SpamAssassin are similar to those of using procmail:

• SpamAssassin offers more flexibility than most mail readers. For example, you can control the exact weighting assigned to each one of the tests that SpamAssassin performs.

• SpamAssassin runs on the mail server, which means it operates on your e-mail as it receives it. A mail reader can only process your messages as it reads them off the server. In particular, if you blacklist an address in ~/.spamassassin/user_prefs, it will be bounced by the mail server and never get into your INBOX.

If you're interested in configuring SpamAssassin, I recommend the following resources:

• The SpamAssassin web page.
• The SpamAssassin Wiki.
• The spamassassin man page.
• WilliamSeligman's SpamAssassin preferences file at ~seligman/.spamassassin/user_prefs.