Increasing qmail sending limits
Overview
The default configuration for qmail on the (dv) Dedicated-Virtual Servers may be considered relatively conservative if you are sending large amounts of email in a short period of time. This article will allow you to send emails more reliably while still maintaining compliance with servers which implement greylisting.
Requirements
Before you start, this article has the following dependencies:
- You must have SSH access set up for root or a sudo user.
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Instructions
To start, run the following commands, line by line:
Please verify that these setting have not already been customized, running the commands will overwrite any changes they have made. The following command will show you whether those files exist:
ls /var/qmail/control | egrep 'timeoutremote|timeoutsmtpd|concurrencyremote'
echo "120" > /var/qmail/control/timeoutremote
echo "120" > /var/qmail/control/timeoutsmtpd
echo "40" > /var/qmail/control/concurrencyremote
The default timeouts are set to 20 minutes, or 1200 seconds. So if the mail server on the other end is not responding, the outgoing email stays in qmail's remote queue for 20 minutes before it fails. By default, there are 20 outgoing slots for email so this can backup quickly. These settings also increase the number of emails which can be sent at one time to 40. These settings should be safe for all (dv) Dedicated-Virtual Servers.
When you have made the changes, restart qmail with the following command:
/etc/init.d/qmail restart
Mail should now begin to process faster on your (dv) Dedicated-Virtual Server.