Hi, 

I have written a trigger and if some criteria is met it will fire an email.Everything is fine in my mail but i am not able to set sender display name also i have set (Email Aministration-->Deliverability-->and unchecked Enable compliance with standard email security mechanisms and Enable Sender ID compliance).Can you please help me out with this?? 

email.setToAddresses( toAddresses ); 
email.setSenderDisplayName ('Company name'); 
email.setUseSignature(false);