Is it possible to put a personal email address on the software except @crm-pour-pme-en?

The Simple CRM email address is only used to store important emails in Simple CRM.

See explanation on: http://www.simple-crm-online.com/test

You will continue to send and receive emails on your usual email and when you ask Simple CRM to write emails for you, it will do so via your usual email address (and software).