[Mailman-Users] mailman on google comput engine

[Mark Sapiro]

On 3/25/19 8:21 AM, Grant Taylor via Mailman-Users wrote:
> 
> Noted.  I think it would be possible to interject a shim between
> fetchmail that would extract what's necessary to speak LMTP to Mailman.


Yes, it would be possible.


> Is the LMTP still STDIN / STDOUT or something else (possibly a Unix
> socket)?


The shim could receive a message on stdin from fetchmail, but it would
have to deliver the message via LMTP (a subset of SMTP) to Mailman's
lmtp runner which listens on a tcp socket, typically localhost:8024.


> I'm trying to understand if I could drive Mailman 3 via Expect.  Not
> that I would.  I'm just wondering if I could.


You probably could if you created an Expect script to speak LMTP. I
think the major issue in this is that fetchmail does not provide the
envelope, so you don't know the actual envelope sender to use in the
LMTP MAIL FROM command. If the MDA that delivered the mail to the remote
mailbox was compliant, it will be in a Return-Path: header in the
message, but otherwise you'd have to fake it by using a Sender: or From:
header. Also, you don't directly know the original recipient, although
you can infer it based on the mailbox you fetched from.

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