Focused catchall ?

Hi,

Normally a catchall mail address catches all mail to unknown addresses
on a particular domain.

I'm looking for a more "intelligent" or focused way of doing this. The
sequence for arriving mail should be:

A) Deliver to known email address
B) If recipient email address is prefixed by a fixed/specifix string
of characters (by say XYZ, eg. XYZtest@domain.com), deliver to
focused_catchall@domain.com
C) Bounce (or deliver to global_catchall@domain.com)

This feature would be very handy when subscribing to newsletters. I
would like to keep track of how my email address gets into the hands
of spammers - when subscribing I would just use
XYZnewslettername@domain.com and not bother to set up a specific POP3
account for each subscription. If the address should be compromised I
could easily tell who gave it away.

Essentially I think the question is about making a distinction between
global catchall for a domain and focused catchall on the account
level.

1) Can this scenario be solved ?
2) Can you tell me wich mail-hotel provider might actually sell such a
product as a dash-board based mail hosting product ?

Kind regards,

/En9ssemand

On 19 Jul 2004 14:12:21 -0700, en9ssemand <en9ssemand@hotmail.com> may have written:
> Hi,
>
> Normally a catchall mail address catches all mail to unknown addresses
> on a particular domain.
>
> I'm looking for a more "intelligent" or focused way of doing this. The
> sequence for arriving mail should be:
>
> A) Deliver to known email address
> B) If recipient email address is prefixed by a fixed/specifix string
> of characters (by say XYZ, eg. XYZtest@domain.com), deliver to
> focused_catchall@domain.com
> C) Bounce (or deliver to global_catchall@domain.com)

qmail does this by default. Each user may have extension addresses.

Assume your email address is: user@domain.tld

You may then supply an address such as: user-newsletter@domain.tld

Delivery instructions are controlled by .qmail-newsletter in the same
directory as that user's .qmail file. You may then specify a
..qmail-default in that user's homedir to catch all extension addresses.
I use this feature myself to tag addresses just as you mention below.

> Essentially I think the question is about making a distinction between
> global catchall for a domain and focused catchall on the account
> level.

Read `man dot-qmail` for details.

> 2) Can you tell me wich mail-hotel provider might actually sell such a
> product as a dash-board based mail hosting product ?

No "dashboard" required. If you are using POP3 for users, there is
generally only one mailbox to deliver to anyhow. symlink .qmail-default
to .qmail and you are done.

Cheers,
--
Brian T Glenn
delink.net Internet Services

en9ssemand@hotmail.com (en9ssemand) writes:

> I'm looking for a more "intelligent" or focused way of doing this. The
> sequence for arriving mail should be:
>
> A) Deliver to known email address
> B) If recipient email address is prefixed by a fixed/specifix string
> of characters (by say XYZ, eg. XYZtest@domain.com), deliver to
> focused_catchall@domain.com
> C) Bounce (or deliver to global_catchall@domain.com)
>
> This feature would be very handy when subscribing to newsletters. I
> would like to keep track of how my email address gets into the hands
> of spammers - when subscribing I would just use
> XYZnewslettername@domain.com and not bother to set up a specific POP3
> account for each subscription. If the address should be compromised I
> could easily tell who gave it away.
>
> Essentially I think the question is about making a distinction between
> global catchall for a domain and focused catchall on the account
> level.
>
> 1) Can this scenario be solved ?

Sure. If you modify your requirements slightly, it's trivial. Instead
of looking for an arbitrary prefix, use "username-". qmail-local
supports "extension" addresses like this, and even implements a
wildcard mechanism. For example, mail to en9ssemand@example.com is
handled by ~en9ssemand/.qmail, and mail to en9ssemand-foo@example.com
is handled by ~en9ssemand/.qmail-foo (or ~en9ssemand/.qmail-default if
..qmail-foo doesn't exist).

I use this feature to subscribe to mailing lists with
de5-list-LISTNAME addresses and register with web sites using
de5-web-WEBSITE addresses. By creating .qmail-list-default and
..qmail-web-default in advance, I can make these addresses up on the
fly and they work immediately. When it's convenient for me, I can
create a specific .qmail-web-example:com file to send the messages to
their own mailbox, bounce them, or send them to the bitbucket.

If you really want to use an arbitrary prefix, that can be
accomplished using the qmail-users mechanism. The downside is that it
requires the qmail admin to set it up, whereas extension addresses can
be set up by the user.

> 2) Can you tell me wich mail-hotel provider might actually sell such a
> product as a dash-board based mail hosting product ?

I don't know any offhand. You could ask the qmail@list.cr.yp.to
list. You can also google for "disposable addresses"--a common term
for this technique. E.g., here's an article I found:

http://www.powertolearn.com/articles..._service.shtml

--
Dave Sill Oak Ridge National Lab, Workstation Support
Author, The qmail Handbook <http://web.infoave.net/~dsill>
<http://lifewithqmail.org/>: Almost everything you always wanted to know.

Dave Sill <MaxFreedom@sws5.ornl.gov> wrote in message news:<wx01xj6dfny.fsf@sws5.ornl.gov>...
>
> Sure. If you modify your requirements slightly, it's trivial. Instead
> of looking for an arbitrary prefix, use "username-". qmail-local
> supports "extension" addresses like this, and even implements a
> wildcard mechanism. For example, mail to en9ssemand@example.com is
> handled by ~en9ssemand/.qmail, and mail to en9ssemand-foo@example.com
> is handled by ~en9ssemand/.qmail-foo (or ~en9ssemand/.qmail-default if
> .qmail-foo doesn't exist).
>
> I use this feature to subscribe to mailing lists with
> de5-list-LISTNAME addresses and register with web sites using
> de5-web-WEBSITE addresses. By creating .qmail-list-default and
> .qmail-web-default in advance, I can make these addresses up on the
> fly and they work immediately. When it's convenient for me, I can
> create a specific .qmail-web-example:com file to send the messages to
> their own mailbox, bounce them, or send them to the bitbucket.
>

I'm afraid that your reply is a little too technical for me (sorry :-)
As I understand your reply user-whatever@domain.tld is delivered to
user@domain.tld. What do you do when an address gets compromised and
you want to prevent delivery to user@domain.tld - set up
user-whatever@domain.tld as a real account and then delete the
contents ?

"Bitbucket" ~ a black hole where all spam can be forwarded to and
automatically deleted ?

>
> > 2) Can you tell me wich mail-hotel provider might actually sell such a
> > product as a dash-board based mail hosting product ?
>
> I don't know any offhand.

I don't have root access to a server - my mail is hosted with a shared
hosting provider and I handled the accounts using a dash-board-like
environment. Thus I cannot control the qmail implementation but have
to rely on the setup everyone else is using.

Your hint about email address extensions seems to be able to do the
trick.

My current provider is not using qmail, so I'm searching for another
provider :-)

Thanks to both Dave and Brian for the replies.

Regards,

/En9ssemand

en9ssemand@hotmail.com (en9ssemand) writes:

> As I understand your reply user-whatever@domain.tld is delivered to
> user@domain.tld.

No, mail to user-whatever@domain.tld is delivered locally according to
the delivery instructions in whichever of the following is found
first:

~user/.qmail-whatever
~user/.qmail-default

If neither exists, then messages to user-whatever bounce.

> What do you do when an address gets compromised and
> you want to prevent delivery to user@domain.tld - set up
> user-whatever@domain.tld as a real account and then delete the
> contents ?

No, you put delivery instructions in ~user/.qmail-whatever that tell
qmail to either silently throw the message away or generate a bounce
message.

> "Bitbucket" ~ a black hole where all spam can be forwarded to and
> automatically deleted ?

Yes, that's the idea. In Unix, /dev/null is often used for that
purpose. In qmail, you simply don't tell it to deliver the
message. For example, if I want mail for de5-foo to be delivered to a
mailbox named Mail/foo, I'd put the following in my .qmail-foo file:

./Mail/foo

If I want mail to de5-foo to bounce I use:

|bouncesaying "invalid address"

If I want to forward it to dave@example.com I use:

&dave@example.com

If I want to silently ignore it, I create a non-empty file that
contains no delivery instructions. Since .qmail files can contain
comment lines starting with #, I use something like:

#throw away mail to de5-foo

"man dot-qmail" explains the details.

> I don't have root access to a server - my mail is hosted with a shared
> hosting provider and I handled the accounts using a dash-board-like
> environment. Thus I cannot control the qmail implementation but have
> to rely on the setup everyone else is using.
>
> Your hint about email address extensions seems to be able to do the
> trick.

Yes, *if* you have the ability to create .qmail* files--either
manually or through a web interface.

--
Dave Sill Oak Ridge National Lab, Workstation Support
Author, The qmail Handbook <http://web.infoave.net/~dsill>
<http://lifewithqmail.org/>: Almost everything you always wanted to know.

Thanks, I'll start searching for a suitable hosting company.

Regards,

/En9ssemand