Postfix

Check mailq

Active emails

qshape active

Deferred emails

qshape deferred

Incoming emails

qshape incoming

Clean mailq

postsuper -d ALL

with same parsing

postqueue -p|grep '@' |awk {'print $1'}|grep -v '@'|postsuper -d -

or

for i in `postqueue -p|grep '@' |awk {'print $1'}|grep -v '@'`; do postsuper -d $i ; done