[otrs] Wrong System-Email after Upgrade

Hello, i am still using otrs 2.2.7 and want to upgrade to 3.1. I just tried to upgrade to 2.2.8 but after the upgrade the following happens: i do have many companies/customers. and each has it's own queue and own system-address. when i login as a customer of company1 and create a ticket, this customer gets a notification with the email-adress(from) of company2. this should not happen, since the companies should not know of each other... how can i fix this? greetings Wolfgang