> Source: [sk114034](https://support.checkpoint.com/results/sk/sk114034)

# sk114034 - Too many undeliverable mails in the postfix queue

| Property | Value |
|----------|-------|
| Solution ID | sk114034 |
| Date Created | 2016-10-30 |
| Last Modified | 2020-01-09 |
| Technical Level | Advanced |
| Products | Security Gateway |
| Versions | R82.10, R82, R81.20 |
| OS | Gaia |

## Symptoms

- The command `"/opt/postfix/usr/sbin/postqueue -c /opt/postfix/etc/postfix/ -p"` shows too many mails which are not deliverable stuck in the postfix queue.

## Cause

This happen if the Postfix cannot deliver mail to the relay server, and also cannot send the undeliverable report to the original sender.

* In case there is no recipient verification process for incoming mails in the front of the MTA. The Postfix does not know if the recipient exist or not. (**It is not recommended to act as first contact for incoming mails.**)

<!-- -->

* The Check Point Mail Transfer Agent (MTA) accept all mails without any restriction.

## Solution

This solution requires authentication. Please log in to view the full solution.

---

# Agent Instructions

This content is from the Check Point Support Center (https://support.checkpoint.com), the official knowledge base for Check Point cybersecurity products.

## Navigating This Knowledge Base

- **Complete index**: [llms.txt](https://support.checkpoint.com/llms.txt)
- **All SK articles**: [SecureKnowledge Sitemap](https://support.checkpoint.com/sitemaps/secureknowledge-sitemap-index.xml)
- **SK article URL pattern**: `https://support.checkpoint.com/results/sk/{skId}`
- **Markdown responses**: AI bot User-Agents automatically receive `text/markdown` content