[Dovecot] deliver rejection bounces
Is there any reason not to make (for v1.2)
deliver -e behavior the defaut?
not even provide the option for the current default (have deliver
send bounces itself)?
The only reason it even works like it does currently is because I just
mostly copied what Cyrus did.
On 1/18/09, Timo Sirainen wrote:
Is there any reason not to make (for v1.2)
deliver -e behavior the defaut?
not even provide the option for the current default (have deliver send bounces itself)?
The only reason it even works like it does currently is because I just mostly copied what Cyrus did.
I think doing so would make the system less flexible, and may make unexpected changes to the way a system is currently working. Some may prefer the flexibility of being able to customize the bounce. Recipients may have made rules in their MUAs based on text in current bounces.
-- Gary V
Timo Sirainen wrote:
Is there any reason not to make (for v1.2)
- deliver -e behavior the defaut?
As long as -e still means EX_NOPERM and a new switch is picked for "send bounce ourselves". (Unless #2 happens.)
- not even provide the option for the current default (have deliver send bounces itself)?
As a mail admin, I never want to see deliver generating its own messages to potentially forged addresses and spamming innocent people. The MTA should do this during the SMTP transaction.
~Seth
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1
On Sun, 18 Jan 2009, Seth Mattinen wrote:
As a mail admin, I never want to see deliver generating its own messages to potentially forged addresses and spamming innocent people. The MTA should do this during the SMTP transaction.
Which MTA tries to deliver the mail during the SMTP dialogue? Neither Postfix nor sendmail does, unfortunately. Well, one would open yet another can of worms, if doing so, I guess.
Bye,
Steffen Kaiser -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.6 (GNU/Linux)
iQEVAwUBSXRG03WSIuGy1ktrAQIgyQf/Y4d/ofYXk4J+NbfEc3I7/ixz+nL0desO /k1lGLP+NrUcEOFFEXArA0HXVt+1qv83fY47MkeZNb6qem0v8s7Ywz09TEzO+jc+ fm0MZIZ+MsR/UnwSEoIrqmnUhatNz7hcHQ0I1RZ/JYWTfY0sVqADvuN6U61GbhE8 4TlRiNQ5S2iIFoWki15++KRZoHKjjJPbBrQxDe8GIC8VnnkbIocMvABZcYxGl2UB 9UXGY/2OLfd3L6Z5a/3E/gZ8KvUjwykb2aHjMcFdY+jLnuWR97lD1FK02dUBczpr ja4Hq1R2X/RwoikUkjeP6O0QBxDLojHxkOCOxlGLmstPKOPC8JRQxQ== =vN28 -----END PGP SIGNATURE-----
You message was rejected by... no thank you, I do not want ever to see
this:
On M 19 Jan, 2009, at 10:24 , Steffen Kaiser wrote:
On Sun, 18 Jan 2009, Seth Mattinen wrote:
As a mail admin, I never want to see deliver generating its own
messages to potentially forged addresses and spamming innocent
people. The MTA should do this during the SMTP transaction.Which MTA tries to deliver the mail during the SMTP dialogue? Neither Postfix nor sendmail does, unfortunately. Well, one would
open yet another can of worms, if doing so, I guess.
he meant SMTP time reject, not bounces or NDR or whatever. Giuliano
Steffen Kaiser schrieb:
On Sun, 18 Jan 2009, Seth Mattinen wrote:
As a mail admin, I never want to see deliver generating its own messages to potentially forged addresses and spamming innocent people. The MTA should do this during the SMTP transaction.
Which MTA tries to deliver the mail during the SMTP dialogue? Neither Postfix nor sendmail does, unfortunately. Well, one would open yet another can of worms, if doing so, I guess.
Bye,
-- Steffen Kaiser
Depends what kind of bounce you mean i.e quota full bounce can be avoided by postfix with vda patch ( which isnt official supported by postfix hackers ) but you cant use an additional lda then ( so you may loose filter stuff ) but in fact if you look in your logs daily and have good Anitvirus and Antispam stuff integrated and setuped ,backscatters by lda are very rare, and mostly have easy solutions, like expand quota, deleting mailboxes etc so its like others said avoid to bounce to spam mails is the most stuff, i.e clamav-milter helps a lot killing worms etc on smtp income level, if sanesecurity is up again this will work again for known spam
Best Regards
MfG Robert Schetterer
Germany/Munich/Bavaria
Robert Schetterer wrote:
Steffen Kaiser schrieb:
On Sun, 18 Jan 2009, Seth Mattinen wrote:
As a mail admin, I never want to see deliver generating its own messages to potentially forged addresses and spamming innocent people. The MTA should do this during the SMTP transaction. Which MTA tries to deliver the mail during the SMTP dialogue? Neither Postfix nor sendmail does, unfortunately. Well, one would open yet another can of worms, if doing so, I guess.
Bye,
-- Steffen Kaiser
Depends what kind of bounce you mean i.e quota full bounce can be avoided by postfix with vda patch ( which isnt official supported by postfix hackers ) but you cant use an additional lda then ( so you may loose filter stuff ) but in fact if you look in your logs daily and have good Anitvirus and Antispam stuff integrated and setuped ,backscatters by lda are very rare, and mostly have easy solutions, like expand quota, deleting mailboxes etc so its like others said avoid to bounce to spam mails is the most stuff, i.e clamav-milter helps a lot killing worms etc on smtp income level, if sanesecurity is up again this will work again for known spam
~Seth
On 1/19/2009 11:51 AM, Seth Mattinen wrote:
Just realize using this patch will void the postfix warranty (you won't get much help on the postfix list)...
--
Best regards,
Charles
Charles Marcus wrote:
On 1/19/2009 11:51 AM, Seth Mattinen wrote:
Just realize using this patch will void the postfix warranty (you won't get much help on the postfix list)...
I've never personally used it so i can't vouch for it (I prefer using a pre-queue interface) but just pointing it out.
~Seth
Steffen Kaiser wrote:
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1
On Sun, 18 Jan 2009, Seth Mattinen wrote:
As a mail admin, I never want to see deliver generating its own messages to potentially forged addresses and spamming innocent people. The MTA should do this during the SMTP transaction.
Which MTA tries to deliver the mail during the SMTP dialogue? Neither Postfix nor sendmail does, unfortunately. Well, one would open yet another can of worms, if doing so, I guess.
Postfix. Will it do it out of the box? No. You can add hooks to Postfix using the pre-queue content filter, milter, access policy delegation or patches so that it can respond with a defer/reject during the SMTP session.
http://www.postfix.org/SMTPD_PROXY_README.html http://www.postfix.org/MILTER_README.html http://www.postfix.org/SMTPD_POLICY_README.html
I'm sure there are tools out there developed to take advantage of these interfaces that do what I'm alluding to, but I don't know any off the top of my head and I can't share mine.
~Seth
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1
On Mon, 19 Jan 2009, Seth Mattinen wrote:
Postfix. Will it do it out of the box? No. You can add hooks to Postfix using the pre-queue content filter, milter, access policy delegation or patches so
So your answer is wrong, Postfix _doesn't_ do it. You can hack it to do so.
So you can hack sendmail. Exim, too, if I remember correctly.
qmail cannot, unless they changed the innerworkings.
Many mail setups cannot because they have a specific mail filter machine (e.g. blackbox / hardware appliance) in front of their delivery MTA.
I'm sure there are tools out there developed to take advantage of these interfaces that do what I'm alluding to, but I don't know any off the top of my head and I can't share mine.
MIMEDefang is a very flexible milter (for sendmail). There had been one or two requests like this on the list, but I did not see any success story, yet.
For simple "to one physical mailbox" messages it would be fairly easy with MIMEDefang actually (the theoretical framework, if it would work is another story). The most important part then would be to determine the actual recipient for sure, e.g. milter gets the RCPT TO value, one has to apply any processing in milter. Then you have to call the LDA and process its results properly. Here you have the security itch that milter and LDA usualy do not run with the same user id, hence, the LDA must be set-uid root or something like that. If the SMTP transaction does not time out - this point is quite problematic if you count mail scanning (virus/SPAM) and delivery (with possible user scripts) together, you can return a 4xy or 5xy reply on failure, or 2xy and discard on success.
Actually, I tried to catch out-going DSNs in MIMEDefang, but failed, because they are not passed through milter (in sendmail anyway).
Bye,
Steffen Kaiser -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.6 (GNU/Linux)
iQEVAwUBSXW3wHWSIuGy1ktrAQIREgf/bl0kb+FffJopFuxOumcKfVNcmjK0x02b GueXYxjnHqN9lyjvcDy8blqd1gDpvCWWqk7LlVLxiMnAiRApsC3FlgbvT1iMX0ad MoeFTEXZyDENOWJgqBJJwn6SJrwqJMcvgW8O8yWL6XoXLw3tX5c43196Re3wevBg ahfKkda65t2Zp02DBCxlNC0GHTXbooAPoeoChemdPV7HiYlxjHLPF6H+24RE+IOU O8DsZcYwbQZE2LZtedBafgGe6v7gGUAXl86jz/GOAwdQyu4HtLkJ9gKOcK9F+5cL SpIQJOueDJ9mvOKN24uMm5yuV8nz1z8S6Jh2DJndeR7pzaC/8l2wsg== =SOfv -----END PGP SIGNATURE-----
On T 20 Jan, 2009, at 12:38 , Steffen Kaiser wrote:
So you can hack sendmail. Exim, too, if I remember correctly.
I would not call that hack in exim case though. It is possible to
avoid all backscatter, first of all by avoiding delivery by an
external programme*. This will still leave the possibility of a
failure in forwarding, but by changing the envelope sender to the
local administrator address (setting errors_to in the delivering
routers) even a failure in forwarding will only cause a locally
delivered failure report. There is no excuse for backscatter and
whoever causes it will likely and rightly end up in some blacklist,
local or distributed, sooner or later.
Giuliano
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1
On Sun, 18 Jan 2009, Timo Sirainen wrote:
Is there any reason not to make (for v1.2)
deliver -e behavior the defaut?
not even provide the option for the current default (have deliver send bounces itself)?
I have no objections again 1) and 2).
But as others said, to remove 2) removes flexibility, e.g. to localize bounce messages :)
And you would need to rewrite lots of advices and documentation. I would defer 1) til v2.0 and add a mandatory option for the operation mode, e.g. if none is specified, deliver could comlpain with 'missing operation mode, did you forgot to specify "--operation-mode bounce-self"?' or something like that.
Bye,
Steffen Kaiser -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.6 (GNU/Linux)
iQEVAwUBSXRIn3WSIuGy1ktrAQKbugf/cCYrWEOYTrLuBi3njWowrJCNAEa9A9Ut awwUm1B+NmfazJttabt0acW12MDmI85G/ZeOrZE/eUEBHmwBVzFoFcrukDp/Za0t bWWBeDkNZtN+hj5g5M/aTR2A3ycrMg1DLSm78WM9rmGh1ubGNFOigSXJ7VUXbgjo UcqWt2PjoTWUGJAFZE8PgHxX25EFt5cQkr7U7PoXUS/d8BqTzcI1/+SnscYH5XcJ cHMHP8Ere8+SWZIpedsaxnQuJ+9FtcsXHnUmQ7VRnMnj0aK47LOV4KYjell2fY2z lUDuo/r9lKLCxUQQKqjMVgjZV6dt9O7Sk+E9xqO64noeSh4azZIF8w== =gn7B -----END PGP SIGNATURE-----
On 1/18/2009 2:58 PM, Timo Sirainen wrote:
- not even provide the option for the current default (have deliver send bounces itself)?
I assume you mean respond with an smtp-reject?
My understanding of 'bounces' is they should only ever be generated by the SENDERS MTA?
--
Best regards,
Charles
participants (7)
-
Charles Marcus
-
Gary V
-
Giuliano Gavazzi
-
Robert Schetterer
-
Seth Mattinen
-
Steffen Kaiser
-
Timo Sirainen