The Boston Diaries

The ongoing saga of a programmer who doesn't live in Boston, nor does he even like Boston, but yet named his weblog/journal “The Boston Diaries.”

Go figure.

Thursday, September 14, 2000

The new technical editor at DaveWorld (you just wouldn't get it)

A mailing list I'm on has its own website which is a collaborative journal.

Because of life, the current technical editor of the site (he who actually puts the entries up) had to take a leave of absence from the position and I volunteered to take over.

First thing first, reorganize the site. There currently is no organization, or rather, it's a flat structure where all the pages are in the top level directory. Not a good thing long term.

Then there's the matter of the HTML …

Expanding on EXPN

Once again Spring is having problems with mailing her journal entries, only this time it's with Yahoo.

What is it? EXPN is all the rage now? Must expand email addresses?

Sigh.

So I decide to fix it once and for all. I check the configuration file for Sendmail and don't see any obvious way to disable the EXPN command. Not wanting to hack the source code to remove the EXPN command I figure the next easiest way is to hack the actual binary and change any occurence of E-S-P-N-NULBYTE such that sendmail will no longer be able to actually respond to the EXPN command. I have some software I wrote years ago that makes this relatively easy to do.

So, I find the occurences of E-X-P-N-NULBYTE and make the changes.

No go. Sendmail still reponds to the EXPN command.

Okay, so next it's occurrences of e-x-p-n-NULLBYTE and that's when I find the curious string “noexpn” in the executable. Hmmmmmmmm … I think to myself. Might there actually be a way to disable the EXPN command?

So I search the site for noexpn and I find this:

PrivacyOptions=opt,opt,…

Set the privacy options. “Privacy” is really a misnomer; many of these are just a way of insisting on stricter adherence to the SMTP protocol. The options can be selected from:

public
Allow open access
needmailhelo
Insist on HELO or EHLO command before MAIL
needexpnhelo
Insist on HELO or EHLO command before EXPN
noexpn
Disallow EXPN entirely
needvrfyhelo
Insist on HELO or EHLO command before VRFY
novrfy
Disallow VRFY entirely
restrictmailq
Restrict mailq command
restrictqrun
Restrict -q command line flag
noreceipts
Don't return success DSNs
goaway
Disallow essentially all SMTP status queries
authwarnings
Put X-Authentication-Warning: headers in messages

The goaway pseudo-flag sets all flags except restrictmailq and restrictqrun. If mailq is restricted, only people in the same group as the queue directory can print the queue. If queue runs are restricted, only root and the owner of the queue directory can run the queue. Authentication Warnings add warnings about various conditions that may indicate attempts to spoof the mail system, such as using an non-standard queue directory.

I don't know if it's A Good Thing or A Bad Thing that you can learn more about a program from scanning the executable than you could probably get reading the documentation.

Obligatory Picture

[It's the most wonderful time of the year!]

Obligatory Contact Info

Obligatory Feeds

Obligatory Links

Obligatory Miscellaneous

You have my permission to link freely to any entry here. Go ahead, I won't bite. I promise.

The dates are the permanent links to that day's entries (or entry, if there is only one entry). The titles are the permanent links to that entry only. The format for the links are simple: Start with the base link for this site: https://boston.conman.org/, then add the date you are interested in, say 2000/08/01, so that would make the final URL:

https://boston.conman.org/2000/08/01

You can also specify the entire month by leaving off the day portion. You can even select an arbitrary portion of time.

You may also note subtle shading of the links and that's intentional: the “closer” the link is (relative to the page) the “brighter” it appears. It's an experiment in using color shading to denote the distance a link is from here. If you don't notice it, don't worry; it's not all that important.

It is assumed that every brand name, slogan, corporate name, symbol, design element, et cetera mentioned in these pages is a protected and/or trademarked entity, the sole property of its owner(s), and acknowledgement of this status is implied.

Copyright © 1999-2023 by Sean Conner. All Rights Reserved.