Mail Services

How to Install and Configure Dovecot IMAP Server on RHEL 8 — step-by-step RHEL 8 tutorial on Progressive Robot

How to Install and Configure Dovecot IMAP Server on RHEL 8

Dovecot is a high-performance, secure IMAP and POP3 server that works seamlessly alongside Postfix to deliver a complete mail server stack on RHEL 8. While Postfix handles sending and receiving mail via SMTP, Dovecot allows mail clients like Thunderbird or Outlook to retrieve messages using IMAP or POP3. Dovecot is also SELinux-aware and actively maintained, […]

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Common Problems 121638

Postfix Queue Backlog Causing Delayed Email Delivery

🟡 Medium   ⏱ 5–30 min  Last verified: 12 November 2020 Affected versions: Debian 9 📖 ~1 min read Table of contents Symptom & Impact Environment & Reproduction Root Cause Analysis Quick Triage Step-by-Step Diagnosis Solution – Primary Fix Solution – Alternative Approaches Verification & Acceptance Criteria Rollback Plan Prevention & Hardening Related Errors & […]

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How to Configure Disk Health Monitoring on Windows Server 2012 R2 — step-by-step Windows Server 2012 R2 tutorial on Progressive Robot

How to Configure Disk Health Monitoring on Windows Server 2012 R2

How to Configure Disk Health Monitoring on Windows Server 2012 R2 Disk failures are one of the most common causes of data loss and unplanned downtime in server environments. Windows Server 2012 R2 provides several built-in mechanisms for monitoring disk health including SMART (Self-Monitoring, Analysis and Reporting Technology) data, storage subsystem event logs, Windows Storage […]

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Common Problems 115608

RHEL 7 service postfix Queue Grows Due to DNS Failure

🟡 Medium   ⏱ 5–30 min  Last verified: 3 October 2020 📖 ~1 min read Table of contents Symptom & Impact Environment & Reproduction Root Cause Analysis Quick Triage Step-by-Step Diagnosis Solution – Primary Fix Solution – Alternative Approaches Verification & Acceptance Criteria Rollback Plan Prevention & Hardening Related Errors & Cross-Refs References & Further […]

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How to Manage Certificates with PowerShell on Windows Server 2012 R2 — step-by-step Windows Server 2012 R2 tutorial on Progressive Robot

How to Manage Certificates with PowerShell on Windows Server 2012 R2

How to Manage Certificates with PowerShell on Windows Server 2012 R2 Certificate management is a critical administrative task on Windows Server 2012 R2 — SSL/TLS certificates secure IIS websites, SMTP relay, LDAPS, Remote Desktop, PowerShell Remoting, and many other services. Without proactive certificate lifecycle management, expired certificates cause service outages, authentication failures, and security warnings […]

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How to Use Windows Memory Diagnostic on Windows Server 2012 R2 — step-by-step Windows Server 2012 R2 tutorial on Progressive Robot

How to Use Windows Memory Diagnostic on Windows Server 2012 R2

How to Use Windows Memory Diagnostic on Windows Server 2012 R2 Memory hardware failures are a common but often overlooked cause of server instability, random crashes, application errors, and data corruption on Windows Server 2012 R2. Unlike many hardware faults that generate clear error messages, memory errors frequently manifest as intermittent, seemingly random BSODs or […]

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Common Problems 115532

Postfix mail queue stuck and undelivered

🟡 Medium   ⏱ 5–30 min  Last verified: 17 September 2020 📖 ~1 min read Table of contents Symptom & Impact Environment & Reproduction Root Cause Analysis Quick Triage Step-by-Step Diagnosis Solution – Primary Fix Solution – Alternative Approaches Verification & Acceptance Criteria Rollback Plan Prevention & Hardening Related Errors & Cross-Refs References & Further […]

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Common Problems 119120

Ubuntu 14.04 LTS Postfix Queue Growth from DNSBL Timeout

🟡 Medium   ⏱ 5–30 min  Last verified: 12 September 2020 Affected versions: 14.04 LTS 📖 ~1 min read Table of contents Symptom & Impact Environment & Reproduction Root Cause Analysis Quick Triage Step-by-Step Diagnosis Solution – Primary Fix Solution – Alternative Approaches Verification & Acceptance Criteria Rollback Plan Prevention & Hardening Related Errors & […]

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How to Configure an SMTP Relay on Windows Server 2012 R2 — step-by-step Windows Server 2012 R2 tutorial on Progressive Robot

How to Configure an SMTP Relay on Windows Server 2012 R2

How to Configure an SMTP Relay on Windows Server 2012 R2 An SMTP relay server acts as an intermediary mail gateway, accepting email from authorised internal systems (applications, printers, monitoring tools, scripts) and forwarding it to its destination — either a smart host (such as Exchange or Office 365) or directly via MX lookup. Every […]

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How to Install GitLab CE on RHEL 7 — step-by-step RHEL 7 tutorial on Progressive Robot

How to Install GitLab CE on RHEL 7

How to Install GitLab CE on RHEL 7 GitLab Community Edition is a complete DevOps platform that bundles source code management, issue tracking, CI/CD pipelines, container registry, and wiki functionality into a single self-hosted application. Installing GitLab CE on Red Hat Enterprise Linux 7 is straightforward using the official Omnibus package, which packages all dependencies […]

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