limit number of recipients when sending?

(sendmail version 8.13.x)

Imagine a list-based email (e.g. students on a course) with many
recipients (an email queued on one machine to be sent to another typically
has several hundred recipients).

"confMAX_RCPTS_PER_MESSAGE" seems to be for the _receiving_ system on such
a link, so that it only accepts 'n' recipients at a time (the sender then
has to re-transmit for the next batch of 'n' and so on). Fine.

But is there a similar option available to set on the _sending_ machine,
so that if the number of recipients to whom it is sending at a given
destination exceeds 'n', it sends it in multiple emails, none of which has
more than 'n' recipients?

I looked in cf/README but couldn't find it. (Probably missed it!)


--

: David Lee I.T. Service :
: Senior Systems Programmer Computer Centre :
: UNIX Team Leader Durham University :
: South Road :
: http://www.dur.ac.uk/t.d.lee/ Durham DH1 3LE :
: Phone: +44 191 334 2752 U.K. :

Re: limit number of recipients when sending?

Post removed (X-No-Archive: yes)

Re: limit number of recipients when sending?

On Thu, 29 Nov 2007, Res wrote:

> On Thu, 29 Nov 2007, David Lee wrote:
>
> > "confMAX_RCPTS_PER_MESSAGE" seems to be for the _receiving_ system on such
> > a link, so that it only accepts 'n' recipients at a time (the sender then
> > has to re-transmit for the next batch of 'n' and so on). Fine.
> >
> > But is there a similar option available to set on the _sending_ machine,
> > so that if the number of recipients to whom it is sending at a given
> > destination exceeds 'n', it sends it in multiple emails, none of which has
> > more than 'n' recipients?
> >
> > I looked in cf/README but couldn't find it. (Probably missed it!)
>
> It works the same, your sendmail server must 'receive' the message itself
> if you set it to 100, it will fail to accept it before 'sending' the
> messages.

Thanks for your response.

Will that necessarily be the case if the incoming message (from some
external machine) goes through alias expansion which turns a single
incoming "alias@..." recipient into multiple outgoing recipients for
onwards delivery to another external machine?

If that alias expands to a large number of things at the same "@..."
destination, how can I ensure that each outbound delivery attempt to that
"@..." is limited to some value 'n'?

--

: David Lee I.T. Service :
: Senior Systems Programmer Computer Centre :
: UNIX Team Leader Durham University :
: South Road :
: http://www.dur.ac.uk/t.d.lee/ Durham DH1 3LE :
: Phone: +44 191 334 2752 U.K. :

Re: limit number of recipients when sending?

David Lee writes:

> (sendmail version 8.13.x)
>
> Imagine a list-based email (e.g. students on a course) with many
> recipients (an email queued on one machine to be sent to another typically
> has several hundred recipients).
>
> "confMAX_RCPTS_PER_MESSAGE" seems to be for the _receiving_ system on such
> a link, so that it only accepts 'n' recipients at a time (the sender then
> has to re-transmit for the next batch of 'n' and so on). Fine.
>
> But is there a similar option available to set on the _sending_ machine,
> so that if the number of recipients to whom it is sending at a given
> destination exceeds 'n', it sends it in multiple emails, none of which has
> more than 'n' recipients?
>
> I looked in cf/README but couldn't find it. (Probably missed it!)

A) It can be configured per (outgoing) mailer.

You can define:
SMTP_MAILER_MAXRCPTS - to limit max number of recipient per one
transmitted message
SMTP_MAILER_MAXMSG - to limit number of messages transmitted over
single SMTP connection
e.g.

define(`SMTP_MAILER_MAXMSG',`20')
define(`SMTP_MAILER_MAXRCPTS',`50')

SMTP_* set the limits for esmtp, smtp, smtp8, dsmtp mailers.
RELAY_* set the limits for relay mailer.
Never senmail versions use esmtp mailer as default for relaying outgoing
messages.

B) Even better method is to make submitting soft do the splitting
without leaving it to sendmail e.g.
http://freshmeat.net/projects/bulkmailer/

--
[pl>en: Andrew] Andrzej Adam Filip : anfi@priv.onet.pl : anfi@xl.wp.pl
Open-Sendmail: http://open-sendmail.sourceforge.net/

Re: limit number of recipients when sending?

On Thu, 29 Nov 2007, Andrzej Adam Filip wrote:

> A) It can be configured per (outgoing) mailer.
>
> You can define:
> SMTP_MAILER_MAXRCPTS - to limit max number of recipient per one
> transmitted message
> SMTP_MAILER_MAXMSG - to limit number of messages transmitted over
> single SMTP connection
> e.g.
>
> define(`SMTP_MAILER_MAXMSG',`20')
> define(`SMTP_MAILER_MAXRCPTS',`50')
>
> SMTP_* set the limits for esmtp, smtp, smtp8, dsmtp mailers.
> RELAY_* set the limits for relay mailer.
> Never senmail versions use esmtp mailer as default for relaying outgoing
> messages.

That looks promising. Thanks. (And now I also see the corresponding
description in the 'Define Mailer' part of the Inst&Op guide. Thanks for
the pointer.)


>
> B) Even better method is to make submitting soft do the splitting
> without leaving it to sendmail e.g.
> http://freshmeat.net/projects/bulkmailer/

We using majordomo and Mailman to do our list expansion, so I need to be
able to ensure this limiting functionality within those machines (incoming
single recipient listname, which Mj/Mm turn into multiple recipients etc.)

Thanks again.

--

: David Lee I.T. Service :
: Senior Systems Programmer Computer Centre :
: UNIX Team Leader Durham University :
: South Road :
: http://www.dur.ac.uk/t.d.lee/ Durham DH1 3LE :
: Phone: +44 191 334 2752 U.K. :

Re: limit number of recipients when sending?

David Lee writes:

> On Thu, 29 Nov 2007, Andrzej Adam Filip wrote:
>
>> A) It can be configured per (outgoing) mailer.
>>
>> You can define:
>> SMTP_MAILER_MAXRCPTS - to limit max number of recipient per one
>> transmitted message
>> SMTP_MAILER_MAXMSG - to limit number of messages transmitted over
>> single SMTP connection
>> e.g.
>>
>> define(`SMTP_MAILER_MAXMSG',`20')
>> define(`SMTP_MAILER_MAXRCPTS',`50')
>>
>> SMTP_* set the limits for esmtp, smtp, smtp8, dsmtp mailers.
>> RELAY_* set the limits for relay mailer.
>> Never senmail versions use esmtp mailer as default for relaying outgoing
>> messages.
>
> That looks promising. Thanks. (And now I also see the corresponding
> description in the 'Define Mailer' part of the Inst&Op guide. Thanks
> for the pointer.)

You have seen "yet another simple *after*" documentation :-)

>> B) Even better method is to make submitting soft do the splitting
>> without leaving it to sendmail e.g.
>> http://freshmeat.net/projects/bulkmailer/
>
> We using majordomo and Mailman to do our list expansion, so I need to
> be able to ensure this limiting functionality within those machines
> (incoming single recipient listname, which Mj/Mm turn into multiple
> recipients etc.)

*SOT* [Slightly Off Topic]:
Are you ready to test new methods of integrating the above mailing list
soft with sendmail?

After seeing recommendations for integrating mailman with sendmail
I am sure "they can be improved" in their sendmail part.

--
[pl>en: Andrew] Andrzej Adam Filip : anfi@priv.onet.pl : anfi@xl.wp.pl
Open-Sendmail: http://open-sendmail.sourceforge.net/