Email messages and attachments can be intercepted as they are sent over the Internet. Many email providers support secure connections for incoming and outgoing email. However, the email protocol has a flaw: it falls-back to unsecure connections if an error happens. Zimbra supports S/MIME a standard for encryption and signing email. By using S/MIME encryption […]
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Zimbra Security and PCI DSS
Emails are accessible to most people anywhere and anytime. However, when it comes to handling sensitive data like credit card information, you need to rethink your messaging options. The Payment Card Industry Data Security Standard (PCI DSS) is an information security framework intended to help merchants and service providers protect credit and debit card transactions […]
Zimbra and Nextcloud deepen integration
Many users run both Zimbra and Nextcloud services and for this reason Zimbra and Nextcloud are partnering up to bring users a better experience. Nextcloud and Zimbra share a common mission – providing the best digital collaboration tools, and keeping data private. That’s why it makes sense for Zimbra and Nextcloud to work together to […]
Zimbra Email Security Webinar Series: TLS and DANE (updated)
Many Zimbra administrators have setup TLS encryption to protect their users’ login credentials and email in transit. But TLS is a complex standard, and often unknowingly misconfigured. Deploying TLS correctly does not require a university degree in cryptography, but rather a working knowledge of some key concepts and awareness of pitfalls to avoid. And, with […]
Are you using zen.spamhaus.org or dbl.spamhaus.org for fighting spam? Pay attention!
Spamhaus is making some changes in their policy enforcement, from their website: Are you currently using the Spamhaus Project’s DNS Blocklists (DNSBLs)? Do you access them via the Public Mirrors, for example, query “sbl.spamhaus.org” or “zen.spamhaus.org”? Do you use Cloudflare’s DNS? If you’ve answered “yes” to all three of those questions, you need to make […]
Configuring Fail2Ban on Zimbra
This article is a how-to guide on installing Fail2Ban to block attacking hosts using a null route or blackhole routes. This can help mitigate brute force attacks on Zimbra. Especially brute force attacks on SMTP are very common. Prerequisite: Fail2ban has been tested in combination with netfilter-persistent and iptables. If you use ufw or firewalld […]