The HTTP Strict-Transport-Security response header (often abbreviated as HSTS) informs browsers that the site should only be accessed using HTTPS, and that any future attempts to access it using HTTP should automatically be converted to HTTPS. What does HSTS do for improving security? You have HSTS configured on Zimbra and have configured a correct TLS […]
Author Archive | Barry de Graaff
Protecting Zimbra with Sucuri web application firewall
By Barry de Graaff on January 11, 2023 in Product News, Partners, PowerTips – Admins, Security & Privacy
You can enhance the security of your Zimbra servers by using a web application firewall (WAF). By using a web application firewall you can add the following protections to Zimbra: Geo blocking, geo fencing Blocking or allow IP addresses Emergency DDoS protection Block anonymous proxies Block top three attack countries Manage HTTP Security Headers Limited […]
How to write to log files from a Zimbra Extension
In MyTest.java you can find some examples of how to write to the Zimbra log files. The most common ones are: ZimbraLog.extensions.info(“this is an info message that will show up in /opt/zimbra/log/mailbox.log”); ZimbraLog.extensions.error(“this is an error message that will show up in /opt/zimbra/log/mailbox.log”); To see the logging in action run a tail on the log […]
Did you know? Zimbra Postscreen provides additional protection against mail server overload
In Zimbra you can optionally enable Postscreen as an additional Anti-SPAM strategy. Postscreen will offer additional protection against mail server overload. One postscreen process handles multiple inbound SMTP connections and decides which clients may talk to a Post-fix SMTP server process. By keeping spambots away, postscreen leaves more SMTP server processes available for legitimate clients […]
Update Zimbra TLS cipher suites to disable Diffie-Hellmann
In a previous blog and wiki we have shown how to configure Zimbra with a strong TLS configuration. Since encryption is always evolving we have updated the previous blog and wiki to disable Diffie-Hellman. If you have applied the steps from the Cipher Suites wiki before, you can run the following commands as user zimbra […]
Email Security Protect your email account and data
Identity theft, fraudulent use of your credit card, ransomware… cybercrime is always evolving. There are some simple things you can do to protect your email data and accounts. How can you protect yourself from the most common and real threats like: Identity and credit card information theft Theft of proprietary data Precise phishing attacks Ransomware […]