Managing the email queue is a critical part of server administration, especially when it comes to identifying and removing unwanted or problematic messages. In this article, we focus on a specific scenario: how to delete emails from the queue in CentOS 7 that originate from a particular sender – for example, This email address is being protected from spambots. You need JavaScript enabled to view it.. This guide assumes the use of Postfix, the default Mail Transfer Agent (MTA) on CentOS 7 systems.

Why Filter and Delete Emails by Sender

Sometimes, the mail queue can be flooded with emails from a single sender. This may happen due to misconfigured applications, testing scripts, or even spam attacks. Manually deleting dozens or hundreds of queued messages is inefficient, so filtering and batch removal becomes essential.

Checking the Mail Queue in CentOS 7

To inspect the current state of the mail queue, use:

mailq

or:

postqueue -p

These commands display all messages currently in the queue, including their IDs, sizes, ages, and sender/recipient addresses.

Filtering Message IDs by Specific Sender

To isolate messages sent by This email address is being protected from spambots. You need JavaScript enabled to view it., use the following command:

mailq | grep -B1 "This email address is being protected from spambots. You need JavaScript enabled to view it." | grep '^[A-F0-9]' | awk '{print $1}' | tr -d '*!' > ids.txt

Here’s what this command does:

• grep -B1 finds all occurrences of the sender’s email and includes the line before (which contains the message ID),

• awk extracts the message ID,

• tr removes any special characters like * or !,

• the output is saved into a file named ids.txt for further processing.

Deleting Messages Using postsuper

Now that we have the list of message IDs, we can delete them from the queue:

cat ids.txt | xargs -n 1 postsuper -d

This command will remove each queued message identified in the file using the postsuper -d utility.

Verifying the Result

After deletion, re-check the queue with:

mailq

If no messages from the specific sender remain, the operation was successful.

Optional: Automation via Shell Script

For repeated use, consider saving the process as a shell script:

#!/bin/bash
grep -B1 "This email address is being protected from spambots. You need JavaScript enabled to view it." < <(mailq) | grep '^[A-F0-9]' | awk '{print $1}' | tr -d '*!' | xargs -n 1 postsuper -d

Save it as remove_from_queue.sh, make it executable with chmod +x remove_from_queue.sh, and run it whenever needed.

Deleting queued messages from a specific sender in CentOS 7 with Postfix is an effective way to keep your mail server clean and responsive. Tools like grep, awk, xargs, and postsuper are essential for every Linux administrator. For production environments, consider integrating queue monitoring into systems like Zabbix or building a script-based automation for detecting and removing suspicious messages.

Proper email queue hygiene not only improves server performance but also reduces the risk of blacklisting due to spam or misrouted emails.