Inspecting Postfix’s email queue.

1-  Display a list of queued mail

mailq

or

postqueue -p

To save the output to a text file you can run

mailq > myfile.txt

or

postqueue -p > myfile.txt

2- View message (contents, header and body) in Postfix queue

Assuming the message has the ID XXXXXXX (you can see the ID form the QUEUE)

postcat -vq XXXXXXXXXX

Or to save it in a file

postcat -vq XXXXXXXXXX > themessage.txt

3- Tell Postfix to process the Queue now

postqueue -f

OR

postfix flush

4- Delete queued mail

Delete all queued mail

postsuper -d ALL

Delete differed mail queue messages

(The ones the system intends to retry later)

postsuper -d ALL deferred