From Newsgroup: comp.mail.sendmail

I'm running Sendmail 8.15.2 with the milter-regex milter, and would
like to set up a "quarantine" queue. As far as I can tell, this works
in three phases:
1) milter-regex asks sendmail to place an offending email in a
quarantine queue,
2) I, as the postmaster, can "release" selected quarantined emails back
into the appropriate "received" queue
(using the "sendmail -qI<id> -Q" command)
3) sendmail, via a queue runner, ages out the remaining quarantined
emails, and ultimately discards the email and sends a bounce message
to the origin.

It's this third part that I have questions about.
1) Do I need a special queue runner to age out the quarantined emails?
I currently have
/usr/sbin/sendmail -L sm-msp-queue -Ac -q25m
running as the sole queue runner; is this adequate?

2) How do I control the aging process? What mc file (or cf file) settings
do I need to tweak? Are there commandline settings to tweak as well?
What are the defaults, how do I find them?

I appreciate any help I can get

Thanks
--
Lew Pitcher
"In Skills We Trust"
Not LLM output - I'm just like this.
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From Newsgroup: comp.mail.sendmail

Lew Pitcher wrote:

I'm running Sendmail 8.15.2 with the milter-regex milter, and would

that's a fairly old version

1) Do I need a special queue runner to age out the quarantined emails?

Yes. See the man page, look for -qQ

2) How do I control the aging process? What mc file (or cf file) settings
do I need to tweak? Are there commandline settings to tweak as well?

Look for Timeout.queuereturn in op.me, e.g.,
4.1.3. Message timeouts
and cf/README.
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From Newsgroup: comp.mail.sendmail

On Sun, 06 Sep 2026 13:41:00 -0400, Claus A|fmann wrote:

Lew Pitcher wrote:

I'm running Sendmail 8.15.2 with the milter-regex milter, and would

that's a fairly old version

Admittedly, but that's not the issue at the moment.

1) Do I need a special queue runner to age out the quarantined emails?

Yes. See the man page, look for -qQ

Could you be a little clearer here? The sendmail(1) manpage doesn't talk specifically about queue runners, and the only example I have (as I posted previously) looks like
/usr/sbin/sendmail -L sm-msp-queue -Ac -q25m
What should the queue runner for the quarantine queue look like?

I've tried
/usr/sbin/sendmail -L sm-quarantine-queue -Ac -qQ -q
and
/usr/sbin/sendmail -L sm-quarantine-queue -Ac -q -qQ
to no avail.

Please note that I'm trying to /understand/ the process. Sendmail setup is (admittedly) quite an arcane and cryptic topic, and I don't have the best offline resources available. So, this forum is the place I look to for
guidance and education.

2) How do I control the aging process? What mc file (or cf file) settings
do I need to tweak? Are there commandline settings to tweak as well?

Look for Timeout.queuereturn in op.me, e.g.,
4.1.3. Message timeouts
and cf/README.

That, I understand. Thank you
--
Lew Pitcher
"In Skills We Trust"
Not LLM output - I'm just like this.
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From Newsgroup: comp.mail.sendmail

On Tue, 08 Sep 2026 13:22:56 +0000, Lew Pitcher wrote:
[snip]

Please note that I'm trying to /understand/ the process. Sendmail setup is (admittedly) quite an arcane and cryptic topic, and I don't have the best offline resources available. So, this forum is the place I look to for guidance and education.

For what it's worth, I'm trying to add another layer of spam filtering to
my sendmail installation, and have decided to try using a quarantine queue
to perform that function. The intent is to trap "borderline" emails in a quarantine queue, and only release those that were "false positives". The remaining emails would remain in the quarantine queue until their queue
expiry time. At that point, if I understand correctly, sendmail will detect that they have waited in the queue past their intended delivery time, and discard the expired email with a "bounce" message back to the originator.

There doesn't seem to be clear instructions on how to set up the quarantine queue and it's associated queue runner, and the 'theory' part of this whole operation seems fragmented and buried in a metric sh&t-ton of documentation.

Yes, I know about the -qQ option, and the -Ac option, and even the -q option, but I cant find anything that ties them together into a coherent "this is how you manage a quarantine queue" operation.

I've tried "trial and error", and got poor results; a quarantine queue that won't bounce emails past their delivery deadline, a queue runner that doesnt seem to do anything, or delivers the expired emails rather than bouncing
them.

Clearly, I don't understand /how/ to operate a quarantine queue, and probably also misunderstand the /options/ surrounding the operation.

The sendmail(1) manual doesn't help, and the Operations manual (op.ps) is
quite dense. I'm working my way through it, and would appreciate some guidance and advice regarding the subject. Can I do what I described above?

I appreciate any advice you can provide.
--
Lew Pitcher
"In Skills We Trust"
Not LLM output - I'm just like this.
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From Newsgroup: comp.mail.sendmail

Lew Pitcher wrote:

On Tue, 08 Sep 2026 13:22:56 +0000, Lew Pitcher wrote:

[that posting is not (yet?) available here.]

quarantine queue, and only release those that were "false positives". The

The quarantine queue is solely for manual operation, i.e.,
you have to look at the items and decide what to do.

remaining emails would remain in the quarantine queue until their queue expiry time.

Only if you explicitly run the queue with the required options.
That is NOT the purpose of quarantining.

There doesn't seem to be clear instructions on how to set up the quarantine queue and it's associated queue runner, and the 'theory' part of this whole

See above.

Anyway:
You already know how to run the submission queue:
/PATH/TO/sendmail -L sm-msp-queue -Ac -q30m
so just look at the man page how to use the quarantine queue:

-q[!]Qsubstr
Limit processed jobs to quarantined jobs containing substr as a
substring of the quarantine reason or not when ! is specified.

So you could use something like

/PATH/TO/sendmail -L q-quarantine -q5h -q!QNOT-A-MATCH

(depending on what you use for as quarantine reason)
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From Newsgroup: comp.mail.sendmail

Lew Pitcher wrote:

/usr/sbin/sendmail -L sm-quarantine-queue -Ac -qQ -q

-Ac Use submit.cf even if the operation mode does not indicate an
initial mail submission.

You don't quarantine mails via submit.cf, right?
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From Newsgroup: comp.mail.sendmail

On 2026-09-08, Lew Pitcher wrote:

... At that point, if I understand correctly, sendmail will detect
that they have waited in the queue past their intended delivery
time, and discard the expired email with a "bounce" message back
to the originator.

AKA backscatter ... You might want to reconsider this part ...
If the messages really are spam, you probably don't want to risk
backscatter for the benefit of adhering to issuing a bounce message.
--
----------------------------------------------------------------------
Sylvain Robitaille syl@therockgarden.ca ----------------------------------------------------------------------
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