The full error in the event viewer is: "Faulting application blat.exe, version 2.6.2.0, faulting module msvcrt.dll, version 7.0.3790.3959, fault address 0x00037e23."
The DOS command script errors with ERRORLEVEL = -1073741819.
Running v2.6.1 solves the problem.
I can't say whay -SaveSettings isn't working. Blat is fussy about syntax, there could be something missing from the command line or there could be atypo, "-pwd" rather than "-pw". Anyway, this will save your settings to the registry:
blat -install smtp.k.net blat@k.com 2 - - cdo@k.com abcdef123
The first standalone dash is the port number. Port 25 is the default...