If you mean you just have an e-mail that says "your're good" I don't think that will do. You need the lab result given from the lab showing the lab name and the lab CLIA number (i.e., the business letter head). Mine was a pdf attached to an e-mail from the lab. I uploaded that e-mail to the usvi travel portal.

Hint - print out that covid test result AND the acknowledgement showing you were accepted by the usvi travel portal (I seem to remember there was a QR code on that acknowledgement but it's been a couple of weeks so my memory may be fuzzy). Much faster to show the health department these pieces of paper than it is to fumble around with your cell phone.