docs/Servers/Email/iRedMail/Query SMTP Outgoing Queue.md

Purpose

You may need to troubleshoot the outgoing SMTP email queue / active sessions in iRedMail for one reason or another. This can provide useful insight into the reason why emails are not being delivered, etc.

Overall Queue Backlog

You can run the following command to get the complete backlog of all email senders in the queue. This can be useful for tracking the queue's "drainage" over-time.

# List the total number of queued messages
postqueue -p | egrep -c '^[A-F0-9]'

# Itemize and count the queued messages based on sender.
postqueue -p | awk '/^[A-F0-9]/ {id=$1} /from=<[^>]+>/ && $0 !~ /from=<>/ {print id; exit}'

!!! example "Example Output" - 10392 problematic@bunny-lab.io - 301 prettybad@bunny-lab.io - 39 infrastructure@bunny-lab.io - 20 nicole.rappe@bunny-lab.io

Investigating Individual Emails

You can run the following command to list all queued messages: postqueue -p. You can then run postcat -vq <message-ID> to read detailed information on any specific queued SMTP message:

postqueue -p
postcat -vq 4dgHry5LZnzH6x08 # (1)

1. Example message ID gathered from the previous postqueue -p command.

Attempt to Gracefully Reload Postfix

You may want to try to unstick things by gracefully "reloading" the postfix service via postfix reload. This will ensure that we don't drop / disconnect / lose all of the active outgoing SMTP sessions in the queue. It may not help resolve issues, but it's worth noting down:

Reattempt Delivery

You can attempt redelivery via running postqueue -f to try to free up the queue. Postfix will immediately re-attempt delivery of all queued messages instead of waiting for their scheduled retry time. It does not override remote rejections or fix underlying delivery errors; it only accelerates the next delivery attempt.