[Techtalk] `TO:' header alias rewrite - Sendmail

[Kai MacTane]

At 3/29/02 05:00 PM , Nosferatu!!! wrote:

>Say I have the following alias definition in /etc/aliases -
>ruby:           rubidium at hotmail.com
>
>Now, sendmail expands the "ruby" to the proper address in "RCPT TO:",
>but, the "To:" header in the message still reads "To: ruby".
>
>Its not a big deal for me except that "ruby" has Hotmail filtering
>on that rejects messages whose "To:" header does not read as
>"To: rubidium at hotmail.com"

I don't know a whole lot about Sendmail. My only suggestion is: you could 
redirect the alias to a program that does the header rewriting and then 
re-sends the mail to the destination. So in /etc/alias:

ruby:    |/path/to/header-rewrite  rubidium at hotmail.com

header-rewrite would then need to take in the mail message on STDIN, get 
the destination email address from the first argument ($ARGV[0] in Perl), 
replace whatever was in To: with said first argument*, and re-send the mail.

Looks to me like about 100 - 200 lines of Perl.

* Note that you may wish to have it only substitute the argument
   contents in for whatever's between any < and > in the To: line.

>Also, I want it to work this way only for selective aliases and not
>for ones like
>
>buddies:        aaa at hotmail.com, bbb at yahoo.com, ccc at rediffmail.com

This script could just as easily be designed to get a list of source and 
destination addresses from some config file, but making it take the 
destination on the command line means that all you need to do is make 
changes in /etc/aliases. This keeps /etc/aliases nice and readable without 
reference to other files.

In particular, the buddies alias isn't affected.

>I know I'll have to write rulesets for that, but, I don't have
>access to the Bat book. Anybody feeling suicidal? ;)

Maybe that's why my initial thought is "a Perl script can fix this". I 
don't have access to the Bat book, and I'm not feeling suicidal. :)

                                                 --Kai MacTane
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