# What OS are you using? # What version of Thunderbird are you using? # What server are you talking about eg: gmail, outlook, yahoo, comcast etc ? # What Anti-Virus are you using ? It would be helpful to see image of the error. If the message states 'Thunderbird' is temp unavailable then it's possible the Anti-Virus is causing a problem because it's scanning every file that gets opened causing delays or Firewall is blocking port. However, until we see the error message it's also possible it's the server that's temp unavailable and that could be due to a block by Firewall etc or server settings not correct etc or server really does have an issue. Always adviseable to dothe following to check nothing is blocking access. '''Firewall:''' Access Firewall - it might be the default supplied with OS or if you installed an Anti-Virus then it's probably controlling the Firewall. You must set up the Thunderbird program as 'allowed'. This will then stop blocking of ports etc. Do not stop Firewall as the default may take over and anyway you need it running. Confirm Firewall has Thunderbird program set as allowed. '''Anti-Virus:''' Access Anti-Virus and set up an exception to not scan your '''Thunderbird''' profile folder. If you download Thunderbird from the official website : https://www.thunderbird.net/en-US/thunderbird/all/ Then default would have put the 'Thunderbird' profile folder here: * C://Users/username/Appdata/Roaming/'''Thunderbird''' Please post info regarding your server settings. Helpful to upload images of 'Account Settings' > 'Server Settings' for the account to this forum question. Also locate and post this info: * In Thunderbird - Help > Troubleshooting Information * Scroll down to 'Mail and News Accounts' * Copy all data in that area and paste it into this forum question.