Qmail – Speedup sending of outgoing mails by rising concurrencyremote
If your qmail queu length keeps growing when sending lots of emails, maybe your concurrent outgoing connections are not enough. So you could rise the limit to a value which will be sufficient.
The default value is “20” concurrent remote connections.
For this purpose execute the following:
echo 100 > /var/qmail/control/concurrencyremote
This will rise the limit to 100 concurrent connection.
Qmail – Change the time email messages can stay at qmail queue
By default Qmail has very long message queue timeout, and messages can stay up to 1 week in the queue.
If you want to shorten the time qmail queue messages can stay in Queue, then you can shorten
queuelifetime, by using the following command:
echo "86400" > /var/qmail/control/queuelifetime
Then restart Qmail