When an order is placed, two emails are generated (in one email marketplace is shown in from while in another, vendor is shown, while both emails are generated fromarketplsce email ID).
We wish that one one email (as per standard of all marketplaces) is generated with marketplace in the from field.
What do you mean by "two e-mails are generated"? In normal conditions, in Multi-Vendor store (I assume that you're using Multi-Vendor, because you're mentioning "marketplaces") customer receives only one e-mail, which comes from vendor e-mail address.
In section Settings -> E-mails there is a checkbox "Send vendor emails from marketplace email addresses" - maybe this one will help you to send e-mails from correct addresses?
You can see that these are two emails, from.one domain info@vliesbig.com, having same contents, but title of first email is showing Skyleadsports which is Vendor and other is showing Valuesbig which is Marketplace
However, in email caption, still vendor name is shown instead of marketplace or no vendor name despite we have removed company name parameter from all order related