This issue has nothing to do with the Program. If all passwords are being stored in Thunderbird and you can see them then it's not an issue with stuff being stored. I'm assuming you have set up all the accounts to use the correct server settings. But you say you have..."all hotmail/outlook mail accounts" What is not known is this: And all of this is a new thing ..... Microsoft says password of hotmail should be the same password as MS oulook.com account. That means all of your outlook/hotmail accounts must use same password for each email address AND and that password matches the MS account password. You said you have done everything, but I need clarity on this, so - as per instructions in my previous comment - have you reset all your outlook/hotmail accounts to use same identical password ? If no...use a browser and access each account and get all set up to use identical password. Please confirm when you have done it. Then... via a browser logon to the MS account - (identical password as all accounts) to see all those alias hotmail etc email addresses. One email address will be set as 'primary' - you can choose whatever is set as primary, but whatever you choose, all email addresses/accounts must use it in the SMTP settings. That means every SMTP for all your accounts must set 'Username' as the 'primary' email address. It means only one of your email address/mail accounts - whatever is set as 'primary' will have incoming and outgoing Username= same account. All other accounts will use a differnet SMTP username - (not the mail account email address that was how it used to be) - it must be whatever is set as 'primary'. That means access: * Account Settings * Scroll to bottom of left Pane and select 'Outgoing Server (SMTP)' Work down the SMTP list for all hotmail/outlook accounts Select smtp and click on 'Edit' * Description = email address of account * Username = whatever is set as primary email address Click on 'OK' So ...as per my previous comment..In Thunderbird, for every email address/account....have you set the SMTP settings to use the 'username' = whatever account is set up as primary? Please confirm.