A script? I doubt it. I would be more inclined to think there were mail sitting in the outbox folder that are send when Thunderbird goes online.

Perhaps you could explain this situation in a little more detail.

Thanks Matt for the shot at a solution. I have never seen anything in my outbox.

Please see attached for a capture of the last couple of days … tens of e-mails sent to the same unknown address.

Are there any ways to do start-up scripts or scripts of any kind in thunderbird? Anyone know?

Regards Dick

Start computer in 'Safe Mode' and run a full scan.

Thanks, How to do that on my desktop Win 10 machine? …

Separately - There seems to be no information on how a script might run as a normal operation in Thunderbird...

Does anyone know? Regards,

re :Start computer in 'Safe Mode' and run a full scan......How to do that on my desktop Win 10 machine?

• https://support.microsoft.com/en-gb/help/12376/windows-10-start-your-pc-in-safe-mode

First, you need to find out if you have got some malware doing it. Hence start up/restart the computer in 'Safe Mode' and then tell your Anti-Virus to run a full scan.