How could I change the sender's name ????

[gmert]

How could I change the sender's name,when I send mass E-Mails from admincp,from: nfo@flowers.com (nfo@flowers.com) to one word: STEVENSON

[gmert]

I tried the following,vBulletin Options > Site Name / URL / Contact Details > Webmaster's Email but did not have any effect What should I do?