isolate the log information for a specific email mailbox into a separate log file

Hi,

I need to give an external consultant access to log files of a specific domain and a specific email mailbox. How can I redirect the logfiles so that they are written to a separate log file and not to the default file /usr/local/psa/var/log/maillog?

if this is not possible ... can I possibly set it for a special domain, that all logs are stored in a separate folder?

thank you for your help.