Need info: On phone and laptop - have you set up IMAP accounts or POP ? If you access your webmail account via a browser, do you see all your emails? On desktop: What OS are you using ? What version of Thunderbird are you using? Please post info: In Thunderbird * Help > Troubleshooting Information * Scroll to 'Mail and News Accounts'. * Post an image showing all the data in that section. When you want to 'Get Messages' or 'Send' what error messages are you getting ? - Post an image of error message or type it exactly word for word verbatim. In Thunderbird * Tools > Developer Tools > Error Console * Clear the error console using the bin icon then close. * Exit Thunderbird. * Then restart Thunderbird and open the Error Console. * Attempt 'Get Messages' * Post an image showing all the info in the error console as it may reveal something important.