1. Charles Duan Harvard Univ. Computer Services March 27, 2002
Using Procmail
Charles Duan
Harvard Univ. Computer Services
March 27, 2002

2. Using Procmail What is procmail? Basic procmailrc recipes
Using patterns
Recipe options
File locking
September 12, 2017September 12, 2017

3. Using Procmail What is procmail? Basic procmailrc recipes
Using patterns
Recipe options
File locking
September 12, 2017September 12, 2017

4. What is Procmail? Procmail is a processor of e-mail
Filter mail by headers/content
Multiple delivery possibilities
Mailboxes
Forwarding Addresses
Programs
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5. Procmail Recipes
Procmail filters s based on recipes in the .procmailrc file
Recipes contain:
What kind of the recipe handles
What to do with the
At most one recipe executes (unless otherwise specified)
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6. Procmailrc Syntax Header Patterns Action # A basic .procmailrc :0:
* ^From:
Patterns
Important-folder
Action
* ^Subject: *\[UA\]
* < 1024 !
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7. Delivering Mail with Procmail
Mail Received
Run .procmailrc
Add to .inbox
Read a “recipe”
No more recipes
No match
Execute action
Match
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8. Using Procmail What is procmail? Basic procmailrc recipes
Using patterns
Recipe options
File locking
September 12, 2017September 12, 2017

9. Basic Procmail Recipes
Sorting Recipes
Forwarding Recipes
Program Recipes
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10. Sorting Recipes Most common recipe used Multiple patterns accepted
:0:
* ^Subject: *\[UA\]
If Subject contains “[UA]”
uas-mail
Put it in mailbox “uas-mail”
Most common recipe used
Multiple patterns accepted
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11. Forwarding Recipes Multiple forwarding addresses accepted:0
Header (no trailing colon)
* ^From: *ksdavis
If it’s from Kevin !
Send it to
Multiple forwarding addresses accepted
Multiple patterns accepted
To keep a copy yourself, use “:0c”
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12. Program Recipes Used for processing online forms
# Forwarding :0
* ^Subject: *Survey
If it’s for the survey
| runstats.pl
Run my program on it
Used for processing online forms
Very powerful; proceed with caution
I’ll talk later about “:0:” v. “:0”
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13. Exercise
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14. Using Procmail What is procmail? Basic procmailrc recipes
Using patterns
Recipe options
File locking
September 12, 2017September 12, 2017

15. E-mail Structure Two parts: header and body Separated by an empty line
Each line of header is “Field: Value”
Special “From” line
Based on Berkeley mbox format
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16. E-mail Structure Example
From
“From” line
From: Aaron Lee
Header
To:
Subject: Interesting ...
Date: Sun, 10 Feb
Blank line
I send you this file in
Body
order to have your advice
I hope you can help me
“From” line separates messages
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17. Regular Expressions “Completely” compatible with egrep
By default, matches only header
Watch out for spaces
* From: Wrong
* From:[ Right!
(That’s a space and a tab in [ ])
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18. Other Special Patterns
! Invert the pattern
? Run a program, use the exit code
< Under specified number of bytes
> Over specified number of bytes
$ Evaluate quotes like /bin/sh
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19. Using Procmail What is procmail? Basic procmailrc recipes
Using patterns
Recipe options
File locking
September 12, 2017September 12, 2017

20. Recipe Options Options placed after zero in header
AaEe: Run based on previous recipe
f: Change (filter) the mail
c: Continue through this recipe
Read “man procmailrc”
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21. Another Exercise
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22. Using Procmail What is procmail? Basic procmailrc recipes
Using patterns
Recipe options
File locking
September 12, 2017September 12, 2017

23. File Locking Prevents procmail processes from corrupting mailboxes
Locking type depends on header
:0 No locking
:0: Default lock
:0: lock Lock the file lock
Not for forwarding, programs (?)
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24. Hints and Tips Test your recipes before using them
Resources for more information
man procmail, procmailrc, procmailex
Have fun using procmail!
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25. The Last Blank Slide
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