Please check the following: '''Firewall:''' Firewall may be controlled by the default installed by OS or it might ve controlled by an Anti-Virus you installed. * Access Firewall and check that Thunderbird program is set up as an allowed program. * If no then set it up. * Please confirm this has been set up. What version of Thunderbird are you both using? Where did you get the Thunderbird installation/download ? Was it from the 'Windows app store' or via the Thunderbird official website: * https://www.thunderbird.net/en-US/thunderbird/all/ Are you both using a '''Pop''' or an '''Imap''' account ? Do you get any pop up error messages when you click on 'Get Messages' ? If yes, upload an image of the error. Are you able to send messages ? Please post the following information: In Thunderbird * Help > Troubleshooting Information * Scroll to the 'Mail and News Accounts' section * Copy all the data and paste it into this forum question OR upload an image file showing the data.