(sorry for my English) # You have uninstalled - on your pc - an email client (Outlook) and installed another email client (Thunderbird): both are programs on your pc. # I presume your email address ends with @outlook.com (otherwise you wouldn't be muddling the server with the client program ;-) ; please, have a - very simple - reading at [https://simple.wikipedia.org/wiki/E-mail https://simple.wikipedia.org/wiki/E-mail] about how email works ) * '''If your email address ends with @outlook.com: ''' in your case, you are using the services of a company called Outlook (owned by Microsoft) which allow you to send email, receive email and remotely store all your messages on their servers (which are located somewhere in USA or around the globe) "Incidentally" you were also using their program (which they have also called Outlook) on your pc to locally manage emails; so your program talk whith Outlook _servers_ and tell it "delete this email, move this email, create this email..." * '''If your email address doesn't end with something else i.e. @gandi.net: ''' you are using services and servers of gandi.net, while using the program Outlook as email client So, you have uninstalled the "email manager" on your pc, not the server. '''Your emails are still there on their servers''', you need the password to access them (with a mail client or webmail) . I believe you saved your password somewhere on you password-manager, on a sheet of paper, on a text file on your pc. If that's not the case, you have to call the customer support of Outlook.com/Gandi.net or whatever your mail provider i ... and hope :-|

Many thanks for your prompt reply. I have now been able to resolve my problem.