i wrote an apex class and created emailservices but it is only working when i send the email to the very long salesforce generated email address and lead is generating but i need to generate lead when i give small address like abc@gmail.com    is this possible?

I want to write a trigger to update field in opportunity(email field) when there is a change in contact  e mail field
relations: lookup from account to contact.  Lookup from account to opportunity.  
  Nb: no relation from contact to opportunity

i wrote an apex class and created emailservices but it is only working when i send the email to the very long salesforce generated email address and lead is generating but i need to generate lead when i give small address like abc@gmail.com    is this possible?

I want to write a trigger to update field in opportunity(email field) when there is a change in contact  e mail field
relations: lookup from account to contact.  Lookup from account to opportunity.  
  Nb: no relation from contact to opportunity