Thank you for the quick answer. It gave me very good clues as to where to start looking.
I read the manual's Email Setup chapter which includes Manual Configuration via AppConfigs and mentions GotOrderEmailTo. Plus I read related articles.
On the dashboard I find the AppConfigs under Configuration > Advanced > AppConfig Parameters
However, this alphabetical list skips from GoogleSiteMap.Xmlns to GraphicsColorDefault -- no GotOrderEmailTo is included, nor are GotOrderEmailFrom nor are GotOrderEmailFromName. Neither are ReceiptEmailFrom or ReceiptEmailFromName. In addition, of the nine MailMe... AppConfigs in the article, only MailMe_Port and MailMe_UseSSL are included.
According to the Email Setup Chapter , I can also modify "Receipt EMail sends from" by going to Configuration > Email and using the Test Wizard form I find there. Clicking "Send Test" saves the entered values to the storefront AppConfigs. However on the Test Wizard page I get an error message "Insufficient Permssions".
In addition, the Mail Server DNS, Mail Server Username, Mail Server Password, and Mail Server TCP Port are not auto-filled with whatever settings are at present in force. And right now I don't have access to the network guys who are the only ones who know these settings. I'm worried that even if I do whatever is necessary to get access, if I fill in only the "Receipt Email sends from (Name)" and click "Test All" that the blank settings will set to blank, wiping out whatever they are now, and I won't be able to re-establish them.
I also tried accessing the Site Configuration Wizard and got an "ERROR: Insufficient Permission!" Right now I'm the only employee working on aspdotnetstorefront. So I've got to find out how to reset permissions -- but that's another whole problem.
Since so many email AppConfigs are missing, I contacted Chat Support and confirmed that it does appear that parts of our system are simply not there. If, for example, we tried to add the shopping cart capability, we'd run into trouble since the basic email setup is not as it should be. So the contact form setup is, indeed, probaby a customized one. It looks like we have a bigger problem than just changing the "From" email address.
Again, thanks for the advice. Even though it didn't give a solution, it certainly helped to clarify the problem.