https://khadirullah.com/tags/security/Recent content in Security on Khadirullah MohammadHugo -- gohugo.ioencontact@khadirullah.com (Khadirullah Mohammad)contact@khadirullah.com (Khadirullah Mohammad)© 2026 Khadirullah MohammadFri, 15 May 2026 00:00:00 +0000https://khadirullah.com/blog/setting-up-custom-domain-email-with-spf-dkim-and-dmarc/Fri, 15 May 2026 00:00:00 +0000contact@khadirullah.com (Khadirullah Mohammad)https://khadirullah.com/blog/setting-up-custom-domain-email-with-spf-dkim-and-dmarc/How I set up professional email on my custom domain using Zoho Mail and Cloudflare DNS — complete with SPF, DKIM, DMARC authentication, alias routing, and folder-based filtering.https://khadirullah.com/blog/how-to-block-internet-access-for-any-linux-app-while-keeping-lan/Wed, 25 Mar 2026 00:00:00 +0000contact@khadirullah.com (Khadirullah Mohammad)https://khadirullah.com/blog/how-to-block-internet-access-for-any-linux-app-while-keeping-lan/Block outbound internet for specific Linux apps using UFW while keeping LAN access. Five approaches from quick wrapper scripts to production-hardened setups — plus the security flaw nobody talks about.