Please remember this is a public forum and you should never post any personal data. All replies are sent via a type of email bot - when a comment is posted it is auto sent via the forum email to whatever email address you used when setting up the mozilla account. People who post comments have no control over what email address is used. No one from Thunderbird nor community helpers etc will ever telephone anyone. So if you get responses from people telephoning you then beware they are not people from this Thunderbird forum community. Likewise if you get emails not sent to the email address you used in creating the Mozilla account then it's not from this forum. '''re :A fault notification comes up advising incorrect username or password.''' That means Thunderbird attempted to access server using the server settings you set up and the server responded with a fault notification. It means: Either password is wrong for that username OR password is correct but not for that username OR both password and username are incorrect OR server setting are not correct regardless of whether password or username are correct or not. I've just checked your forum profile and notice you have had an issue for a wile, but you seem confused. ''I have changed my password through your system but neither my new, or previous, passwords allow me access.'' You can only set/modify a password via the webmail account of the relevant server accessed using a browser. Then you can edit the stored password in Thunderbird to match it. You cannot simply change a password in Thunderbird and expect it to work unless you have already modified the password in the webmail account. ''Alternatively, please transfer my account back to Heart Internet, or another operator that will provide me with continuous access to my emails.'' Heart Internet is a provider of domain names, webhosting and virtual private servers and you seem to have transfered to CloudTech24. Thunderbird is not a server nor an operator nor a provider of domain names, etc - it is just an email client program running on your computer which faciliates accessing various mail accounts all in one location, so you do not need to logon to various web accounts. Judging by the comment: ''I was issued with information sheets headed, "CloudTech24 Email Setup on Laptop with Thunderbird" '' I presume you have a business email account with CloudTech24. They offer Microsoft account and Gmail Workspace accounts etc. I notice in another question you mentioned a hotmail address, so that means I know you have a Microsoft Account. Did you set up the business account to use the Microsoft server ? Is your business email address on an office365 server ? At tihs point I'm assuming this might be the case. Logon to the Microsoft Account webmail account- Can you see the business email address listed ? Is should be listed as an alias account along with the hotmail email address. All accounts in a Microsoft account are seen as 'alias' accounts by Microsoft. All email addresses in the Microsoft account must use the same password as the Microsoft account - so please make sure that is set up correctly. Also email clients use SMTP to send mail - Microsoft only allow people to send using whatever account is set up as the 'Primary' account. You can choose the 'Primary ' account, but if you use hotmail as primary then all emails must be sent via hotmail address - but in Thunderbird you can set a Reply-to to use the business account. What account is set up as primary - business or hotmail ? I need to know what server settings they advised you to use. Please post the following information so we can check on the basic server settings. In Thunderbird Help > Troubleshooting Information Scroll down to 'Mail and News Accounts' setion Copy all the data in that section and paste into this forum question - do not start another question. Alternative - post an image showing that data.