sendmail && dhcp

[Perry Hutchison]

Matthias Apitz <guru at unixarea.de> wrote:
> El d??a Friday, February 27, 2015 a las 01:06:09PM -0800, Perry Hutchison escribi??:
> > ... depending on how you have it configured, mutt may *currently*
> > be running a sendmail process (via fork/exec) for each message you
> > send, rather than using the local sendmail daemon.
>
> mutt uses sendmail (i.e. pipes the mail to something like 
>'sendmail -t -f ....) which queues the mail for further delivery ...

Yep.  mutt is invoking sendmail directly to queue the outgoing message.
It's not using the daemon.

> and this is what I want: queue all the answered mails until I open
> the Wifi uplink and all answers are going out at once. I think,
> this is only possible with a configured sendmail daemon and queue
> runner.

You do need sendmail configured (sendmail.cf set up appropriately),
and you do need to run the queue when you're ready to transmit the
outgoing messages, but you don't need the daemon.  When the Wifi
link comes up, instead of restarting a daemon, all that's needed is
to run "sendmail -q" or "sendmail -qf".  The advantage of the -qf
form is that -- if I'm reading the manpage correctly -- it won't
return until everything has been sent (at which point you can shut
down the link, unless it's being used for something else -- like
incoming messages).

A sendmail daemon is useful in an always-connected system, to
receive messages that someone pushes to it via SMTP or to retry
queued transmissions periodically if the receiving system (or the
path to it) was down on the first attempt.  As the first responder
was saying, it's really not all that useful on a system that is
connected to the Internet only occasionally.