While trying to send mails using QMAIL and PLESK I am getting the error below :

There was an error sending your message: sendmail returned error code 111

Solution :

If any error try stopping QMAIL.

cd /var/qmail/bin

cp -p qmail-local.moved qmail-local
cp -p qmail-remote.moved qmail-remote
cp -p qmail-queue.moved qmail-queue

killall qmail-remote qmail-queue qmail-local
ls -la qmail-queue qmail-local qmail-remote
-r-xr-xr-x 1 root qmail 44060 Jun 13 2006 qmail-local
-r-s--x--x 1 qmailq qmail 15784 Jan 26 14:06 qmail-queue
-r-xr-xr-x 1 root qmail 43364 Jun 13 2006 qmail-remote
Or for other email errors like :
Plesk Qmail error – 451 qq internal bug (#4.3.0)
or
qmail-inject: fatal: qq internal bug (#4.3.0)
we can try the above fix
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