Marko Toivanen <mtoivane @
>How do you folks feel about sites trying to send automatic
>unsu**cription commands instead of delivery failure
>notifications when bouncing list mail because of non-existent
>users? A future paradise for list-managers or more heat to the
>usual purgatory of list management?
I think the efforts should be concentrated in making error messages
in a standard format that is easier for a machine to parse (perhaps with
numeric codes, etc.). Then it will be relatively simple for the *list
management software* to auto-delete (if so enabled) when a bounce
arrives to the owner-listname address.
This approach has several advantages:
- Standard format error messages have potential benefits beyond
just mailing list unsubscriptions
- You don't need an expert system at every node trying to figure out
what command needs to be sent to which address, and the associated
syntax, based on it's guess as to which software at which site
is running the list!
- The ability to do remote unsubscriptions has got to open a security
loophole--maybe this exists anyway for lists that have open
subscriptions and unsubscriptions, but an auto-delete implemented
by the list management software would not force one to choose between
auto-deletion and having a closed list.
Although listserv has such a feature (and some swear by it), I find it
of limited use because:
1. It acts immediately, and there are too many transient situations
in which a host or user is thought of as unknown when in fact it is
not. Ideally, there should be a programmable (on a list basis)
number of consecutive days or bounces after which the user is
auto-deleted (yes, I know this means a per-subscriber count field,
and some way of resetting it once the bounces stop).
One could set this to 0, if one wanted (immediate action), but I'd
probably set it to 1 day (i.e., if the error condition persists for
two consecutive days), and lower-volume lists may well be willing to
give it a few days more to clear.
2. It only handles a small fraction of the bounces, in particular not the
"Cannot send message for n days" variety, which is among the most
frequent and annoying. This is not really within the control of the
software as much, because of the plethora of formats in which this
message may appear--that's where the standard error message format