[[:start|Home]] > [[:faq|FAQ]] > [[faq:email|Email]] > [[faq:email#email_clients_mobile|Email Clients & Mobile]] > [[faq:email#mail_client_issues_and_troubleshooting|Mail Client Issues and Troubleshooting]] > **How to install the new root certificate for Mac OS** ====== How to install the new root certificate for Mac OS ====== This article shows you the steps on how to install the new root certificate -- **ISRG Root X1** -- on your Mac OS device. 1. Download the certificate from this link: http://vo.agnx.com/isrgrootx1.der 2. Once the certificate is downloaded, double click to open it via Keychain Access. {{:faq:profile:install-root-cert:macos:2.png|}} 3. When prompted to provide a name and password, type the name and password for an administrator user on this computer. Then, proceed by clicking on [Modify Keychain]. {{:faq:profile:install-root-cert:macos:3.png|}} 4. The certificate is installed in your Mac OS device. {{:faq:profile:install-root-cert:macos:4.png|}}