[Discuss] extra security on Thunderbird outgoing mail (SMTP)?

[Gordon Craig]

I've run into a problem installing Thunderbird on my Linux Mint 17.2 
tower computer, from "new homes for old computers", First it wanted a 
mail spooler program which I knew nothing of; now it refuses to send 
mail, via SMTP, because of a 'security problem'.
Apparently it wants some kind of password for the SMTP part of 
Thunderbird, but none of the options in the install which include that 
work with Shaw's version. What to do?
I'm using my palmtop instead to try to get the message out because I 
can't send with my principal one!

Gordon