[Mailman-Users] FW: -EXT-Re: Any scripting available for server site admin

Mark Sapiro mark at msapiro.net
Tue Jun 5 20:35:35 EDT 2018

On 06/05/2018 04:54 PM, Parker, Michael D. wrote:
> Hmmm.....I also note something interesting about find_member, it treats email addresses with different character case-ing differently.
> Thus Michael.d.parker at ga.com lists are put in a separate grouping from michael.d.parker at ga.com lists.
> Do email user addresses out there on the web support names in this manner differently?  Off hand, I cannot think of a mailer that does this these days.

RFC 5321 (sec 2.3.11) and predecessors say:

   The standard mailbox naming convention is defined to be
   "local-part at domain"; contemporary usage permits a much broader set of
   applications than simple "user names".  Consequently, and due to a
   long history of problems when intermediate hosts have attempted to
   optimize transport by modifying them, the local-part MUST be
   interpreted and assigned semantics only by the host specified in the
   domain part of the address.

Sec 4.1.2 further defines and qualifies local-part as

   Local-part     = Dot-string / Quoted-string
                  ; MAY be case-sensitive

but adds

   While the above definition for Local-part is relatively permissive,
   for maximum interoperability, a host that expects to receive mail
   SHOULD avoid defining mailboxes where the Local-part requires (or
   uses) the Quoted-string form or where the Local-part is case-

What this all means is local-parts may be case sensitive allthough it is
recommended that they not be. Most if not all major ESPs treat
local-parts case insensitively, but it is not a requirement. In other
words, Michael.d.parker at ga.com and michael.d.parker at ga.com may or may
not refer to the same mailbox, but only qa.com can say which.

>From Mailman's point of view, we use lower-case email addresses as keys
so it is not possible for two members of a single list to have email
addresses that differ only in case, but we remember the case-preserved
address and use that for sending mail. Thus, you can be a member of one
list with the case-preserved email Michael.d.parker at ga.com and a member
of another list with the case-preserved email michael.d.parker at ga.com.

Mailman 3 is different. there would be one global user, possibly with
multiple email addresses, but they should all be case-insensitively
distinct, and that single user can be a member of some set of lists, and
an owner of some, possibly overlapping set of lists and possibly other
roles like moderator or non-member allowed to post.

Mark Sapiro <mark at msapiro.net>        The highway is for gamblers,
San Francisco Bay Area, California    better use your sense - B. Dylan

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