Attach not working [win10]

[bcosell]

I'm trying to make an email message with an attachment . I'm using the command:

mailsend.exe -ct 600 -read-timeout 600 -smtp SMTPSERVER -ssl -port 465 -auth -domain MYDOMAIN +bc -f MYEMAIL -mime-type "text/plain" -name MYNAME -user SMTPACCOUNT -pass SMTPPASSWD -to ME -sub "attachment test" -msg-body d:/desktop/message.txt -v -aname "attachment" -attach "d:/desktop/attachment.txt,text/plain" -show-attach

and in the verbose output I get:

From: ME
Date: Mon, 16 May 2022 12:59:25 -0400
To: ME
X-Mailer: @(#) mailsend v1.20b (Windows)
X-Copyright: BSD. It is illegal to use this software for Spamming
[C] Welcome
[C]
[C]

[C] .
[S] 250 2.0.0 Ok: queued as 4L257y4jmKz1Wq
[C] QUIT
[S] 221 2.0.0 Bye

Notice: no attachment [and I can confirm that the email arrived un-attached-to. What did I do wrong?