Wietse:
> Postfix (or SMTP) supports neither uploading nor fetching, but that
> has not stopped people from implementing that over SMTP. 25 Years
> ago, people would set up all sorts of email aliases that would
> deliver an email message to a local program that would respond with
> a new email message.
>
> Some of that functionality still exists today as part of mailing
> list managers (for example, to retrieve archived list messages) and
> "ftp over email" tools. All this can be implemented without having
> to change any source code of Postfix (or of any competent MTA).
Tom Maier:
> Do you have any sources (e.g., project names) about that? I would like
> to read more about those approaches.
GNU mailman, Majordomo, Ezmlm, Listserv, ...
> Within my uni project I have to implement additional SMTP commands in
> order to upload or download data (e.g., base64 encoded data). This is
> why my initial idea was to add functionality to the smtpd server of
> Postfix by defining a SMTP service extension. Thus it would be possible
> to provide the "upload" command only for previously authenticated users.
> As opposed to this the "download" command is available for everyone.
> What do you think about this concept?
I don't have to do your home work. But consider the following. SMTP
was designed to implement a store-and-forward infrastructure, i.e.
nothing that remotely resembles 'upload' and 'fetch' functionality(*).
In the context of SMTP, those things have been implemented through
add-on programs that process email messages that are sent to a
specific email address.
(*) Old farts might point to the TURN command. That was never
implemented at any significant scale.
> > But, in in this day and age, setting up a web service might be
> > easier.
> Unfortunately the task is very specific about this. I have to implement
> the mentioned features by implementing additional FTP commands.
In computer science, the most difficult problem is to solve the
right problem. Then there is giving meaningful names to things,
and handling errors. I think you're still at the first problem.
Wietse
