2017-05-31 Exported the registry key as per the BLAT FAQ from the old server and imerged it: http://www.blat.net/?faq/index.html#where_and_how_does_blat_save_the_install_configuration but it didn't seem to like it. So I installed it manually: c:\autotask>blat -install cas.victrack.com.au david.cain@victrack.com.au Blat v2.6.2 w/GSS encryption (build : Feb 25 2007 12:06:19) SMTP server set to cas.victrack.com.au on port 25 with user david.cain@victrack.com.au, retry 1 time(s) Test email sent: c:\autotask>blat -bodyF ElecDBody.txt -to QSM-DirectoryUpdate@victrack.com.au -bcc david.cain@victrack.com.au -f robyn.douglas@victrack.com.au -subject "New Directory update" -attach Z:\elecdir\fulldir\elec_dir.zip Blat v2.6.2 w/GSS encryption (build : Feb 25 2007 12:06:19) Sending ElecDBody.txt to QSM-DirectoryUpdate@victrack.com.au, david.cain@victrack.com.au Subject: New Directory update Login name is robyn.douglas@victrack.com.au Attached binary file: Z:\elecdir\fulldir\elec_dir.zip The SMTP server does not like the sender name. Have you set your mail address correctly? Error: Connection to server was dropped. Which proves that the REG keys are good, but mail is denied as a relay (also good as i haven't set it yet). New unobtrusive test: blat -bodyF ElecDBody.txt -to david.cain@victrack.com.au -f robyn.douglas@victrack.com.au -subject "New Directory update" -attach Z:\elecdir\fulldir\elec_dir.zip All good after relay added to mail servers.