Hi !
Unless you mark a delivery agent as "expensive", sendmail will forward the mail immediately. Sometimes this is not possible and the mail is saved in a queue. Check the SENDMAIL_ARGS parameter in /etc/sysconfig/sendmail for something like "-q30m".
You were right, "-q30m" ist given as an argument in /etc/sysconfig/sendmail. So, does this argument reroute outgoing mail if there is a problem with the ISP`s mail server ? If so, what can I do to flush the resulting queue from time to time, say once a week ? Another question : the things mentioned above only apply for outgoing mail, right ? But I also received mails that were months old when I rebooted my router recently. Is it for the same reason, or is there something else I should know/change in sendmail ? BTW, sorry for any rookie questions but I became admin somewhat out of the blue and have been learning by trial and error ever since, no background knowledge.:( Thanks for the help, Jörg