mn :: comp

Why Reply-To Usage Has No Place in Mailing Lists

<RANT>This is a religion issue, really. I usually try to avoid those and live quietly with my choices, but this one bugs me because it causes either needlessly duplicated mail or replies to questions to be unpublished/unarchived.

The RFCs for mailing lists and many MUA authors/contributors feel that mailing lists should not munge REPLY-TO because the end-user and MUA set it and no other authority should be able to override that desire.

The administrators of and frequent contributors to mailing lists love reply-to munging because it prevents needless duplication of mail and helps to keep discussion threads in the mailing list, where they can be archived and publicly posted.

On the one hand: pedantically correct behavior; on the other: rule-bending for the sake of practical usage. The pedantics will rightly point out that workarounds exist. For instance:

• In order to avoid seeing the needless duplication of email, simply have every user of the mailing list set up their own Unix mail server where they can install procmail and configure it to find and delete duplicated email. In order to make sure that everything is archived simply instruct all list users to always use reply-all, at which point another set of people is going to get upset because they're getting duplicate messages, at which point everyone else flames them for not have their own Unix mail server and procmail setup :-)
• Add an option to all MUAs for over-riding Reply-To and educate users to use this option. In Evolution it's right-click the message and choose Reply to List. A fine workaround, though the workflow is unacceptable:
  
  1. decide to reply.
  2. click reply.
  3. write message.
  4. click send.
  5. realize that it didn't go to the list.
  6. investigate why in "Sent".
  7. start a new reply using To-List workaround.
  8. copy and paste from Sent into a new mail message.
  Steps 5 through 8 of course very rarely get done, in which case the answer doesn't get archived, the conversation thread is not public, and the usefulness of the mailing list is decreased.

The best solution? Removing reply-to functionality from MUAs is tempting but impractical; even though it is almost an anachronism in today's world of ubiquitous email services, those who rely on it do rely on it. Removing reply-to munging from MLM software would represent a pretty ugly choice for the reasons above. Know any ISPs or mailing-list owners that would be happy about a useless two-fold increase in the amount of legitimate email traffic? I know I wouldn't be. Changing the standard so that MLMs are allowed to munge reply-to but MTAs are still prohibited? Sounds reasonable to me, and no one has yet given me a valid reason not to (which doesn't mean that it doesn't exist).

I know I'm tilting at a windmill, but I'm going to continue doing so as long as the accepted workaround is for the recipient to take action in order to fix an attempted source-routing of email. Now if the sender's MUA was able to avoid setting Reply-To: when sending to mailing lists, we'd be out of this situation. In my opinion, it is not a mailing list's config which is broken, but rather the standard which they are rightly not adhering to; just as anyone who fully adheres to the IP RFC's non-contiguous subnet mask guidelines needs to have their head examined.</RANT>

Last modified: Nov 25, 2005 12:48 pm. Contact me.