I have setup a new password with my provider and used it with thunderbird.

Please explain in more detail what that means.

I can receive mail with the new password,

Did Thunderbird prompt you for the new password?

I can not ... send e-mail, the same as before.

Did Thunderbird prompt you for the new password?

In your account settings for the Outgoing Server, make sure 'Authentication method' is set to 'Normal Password'.

I thought if I deleated thunderbird and the reinstalled it, everything might work ok.

Thunderbird separates the program installation from your data. The latter is stored in a so called profile and includes all your settings, account information, mail, etc. Reinstalling the application will not touch the profile. When the problem is clearly in the profile, re-installing the application will be a waste of time.

when trying to send an e-mail an error message "outgoing server (SMTP) password required." I could not remember my old password, so I got a new one from my provider. Mozilla posted the error message as far as I know. I checked my Outgoing server account and it is set a "Normal Password.

Have you updated the password here:

'Menu icon' > 'Options' > 'Options' > 'Security' > 'Passwords' tab click on 'Saved Passwords' click on 'Show Passwords'

Select the smtp line for that mail account. right click on the highlighted line and select 'Edit Password'. Type in the new password. click on 'OK'

click on 'Close' click on 'OK'.