I really dislike qmail. But, since I use Plesk, I’m stuck with it. However, I found a way to improve it’s awful mail queue performance by putting the mail queue onto a ramdisk. This is actually pretty darned easy to do.
First, toss a line like this into your /etc/fstab:
none /mailqueue tmpfs defaults,size=100m,nr_inodes=999k,mode=775 0 0
This will make a 100MB ramdisk on /mailqueue. Now, just symlink /var/qmail/mqueue to /mailqueue and move your e-mail over:
# mount /mailqueue # chmod 750 /mailqueue # chown qmailq:qmail /mailqueue # mv /var/qmail/mqueue /var/qmail/mqueue-old # ln -s /mailqueue /var/qmail/mqueue # rsync -av /var/qmail/mqueue-old /mailqueue
This has significantly cut the iowait on my server during heavy e-mail periods. In addition, tools like qmHandle now fly through my mail queue and give me reports very quickly.