Ævar Arnfjörð Bjarmason <avarab@xxxxxxxxx> wrote:
> Add a --send-delay option with a corresponding sendemail.smtpSendDelay
> configuration variable. When set to e.g. 2, this causes send-email to
> sleep 2 seconds before sending the next E-Mail. We'll only sleep
> between sends, not before the first send, or after the last.
>
> This option has two uses. Firstly, to be able to Ctrl+C a long send
> with "all" if you have a change of heart. Secondly, as a hack in some
> mail setups to, with a sufficiently high delay, force the receiving
> client to sort the E-Mails correctly.
>
> Some popular E-Mail clients completely ignore the "Date" header, which
> format-patch is careful to set such that the patches will be displayed
> in order, and instead sort by the time the E-mail was received.
>
> Google's GMail is a good example of such a client. It ostensibly sorts
> by some approximation of received time (although not by any "Received"
> header). It's more usual than not to see patches showing out of order
> in GMail. To take a few examples of orders seen on patches on the Git
> mailing list:
>
> 1 -> 3 -> 4 -> 2 -> 8 -> 7 (completion by Nguyễn Thái Ngọc Duy)
> 2 -> 0 -> 1 -> 3 (pack search by Derrick Stolee)
> 3 -> 2 -> 1 (fast-import by Jameson Miller)
> 2 -> 3 -> 1 -> 5 -> 4 -> 6 (diff-highlight by Jeff King)
>
> The reason to add the new "X-Mailer-Send-Delay" header is to make it
> easy to tell what the imposed delay was, if any. This allows for
> gathering some data on how the transfer of E-Mails with & without this
> option behaves. This may not be workable without really long delays,
> see [1] and [2].
Aside from the new header, I think this is better implemented
using the existing $relogin_delay and $batch_size=1.
Disconnecting during the delay might be more sympathetic to
existing mail servers (which aren't C10K-optimized). If the
client sleeps, the server may disconnect the client anyways
to save resources.
> @@ -1741,6 +1747,10 @@ sub process_file {
> $message, $xfer_encoding, $target_xfer_encoding);
> push @xh, "Content-Transfer-Encoding: $xfer_encoding";
> unshift @xh, 'MIME-Version: 1.0' unless $has_mime_version;
> + if ($send_delay && $i > 0) {
> + push @xh, "X-Mailer-Send-Delay: $send_delay";
> + sleep $send_delay;
> + }
We can add this header for relogin_delay + batch_size
But maybe --send-delay can be a shortcut for
--relogin-delay and --batch-size=1
