Hi,
The plugin attach serial can be configured to send the image in the email and to authorize the download.
If you authorize the download and do not put the virtual file in the product ; the user won't be able to download it.
So you can use the variants if you want to let the image be downloadable or not.
But there is nothing in the plugin "attach serial" to change the setting for the "email" depending a product value.
The solution at this moment will be to use variants and have two different packs ; one which will send the email and another with just the download.
Regards,
Jerome - Obsidev.com
HikaMarket & HikaSerial developer / HikaShop core dev team.
Also helping the HikaShop support team when having some time or couldn't sleep.
By the way, do not send me private message, use the "contact us" form instead.