Here's a little tutorial I just wrote on how to get + syntax in your email addresses. It's a more reliable way of inserting aliases into a remailer than using the comment capability of the address format. This way mail to, say, hh+joebob@soda.berkeley.edu could get delivered to whoever was behind the joebob name, by whatever arrangements have been made. The document is written in such a way that you can send this to your sysadmin intact and ask them to install it for you. Eric ----------------------------------------------------------------------------- How to add + to your email syntax --------------------------------- Ever wanted one of those cool <user+@domain> addresses? So you can use <user+loud_mailing_list@domain> and get a filter to easily move the list out from your regular mail? Now you can. This tutorial works if you're running a fairly standard version of sendmail. It requires some hacking to sendmail.cf, so you need the permission to do that; that's usually root. The modifications are fairly straightforward. I. Add + to the list of operator symbols. The sendmail 'o' macro determines how to break up strings in sendmail.cf rules into tokens. In order to be able to recognize + specially, you'll have to add to the operator symbols to make it separately recognizable. So, first do a % grep -n ^Do sendmail.cf 116:Do.:%@!^=/[] Now, go in and edit line 116 and add a + sign at the end: Do.:%@!^=/[]+ That's all. Now sendmail will not include + inside of its tokens. II. Duplicate local delivery rules to accept + syntax. Sendmail is a delivery multiplexer. You want to change the syntax for local deilvery, so all you need to change is the local mail specifications. First, make sure your local mailer is called 'local'. You can search for the mailer definition as follows: % grep ^Mlocal sendmail.cf Mlocal, P=/usr/libexec/mail.local, F=lsDFMmn, [...] I've elided the tail end of the line, because all you really need to ascertain is that the local mailer has the right name. Now you want to search for all the delivery rules that deliver mail to the local mailer: % grep -n '#local' sendmail.cf 563:R$-<@$w> $#local$:$1 585:R$-<@$D> $#local$:$1 user@ah.com 614:R$+ $#local$:$1 everything else I have three rules for local delivery. (The second one is custom, and allows for delivery to a domain address for which no IP address exists.) All you do now is to add a rule for '+' delivery for each kind of existing local delivery. After I changed mine, it said: % grep -n '#local' sendmail.cf 563:R$-<@$w> $#local$:$1 564:R$-+$*<@$w> $#local$:$1 586:R$-<@$D> $#local$:$1 user@ah.com 587:R$-+$*<@$D> $#local$:$1 user@ah.com 616:R$-+$* $#local$:$1 everything else 617:R$+ $#local$:$1 everything else Rules that matched "$-", a single token, I changed to match "$-+$*", a single token followed by "+" followed by zero or more tokens. Rules that matched "$+", one or more tokens, I changed to match "$-+$*", same as above. I added the changed rule _before_ the original rule because otherwise the $+ would swallow up everything. The $1 in the second column refers to the first macro to match in the pattern in column one. That's the username the mail gets to delivered to. If you have more complicated usernames, you're likely already a seasoned sendmail trooper. III. Install and Test You should probably increment the version number when you make the change. It's in the 'Z' macro, do % grep -n ^DZ sendmail.cf 104:DZ2.06 Freeze the sendmail configuration with sendmail -bz otherwise your changes won't take effect. Now send yourself some test mail and make sure it works. Eric Hughes hughes@ah.com 17 February 1994