How customer can send with their own email address?


I apologize in advance if this topic has already been discussed but I can not find clear answers.

In the case of using MailWizz in SAAS, what is the procedure for the end customer to use his own sender email address?

According to my tests for now, even if the address is changed during the creation of the campaign, it is the address of the system delivery server that is used during the expedition.

I really would have to create a delivery server account for each customer and dedicate it to him?
Each delivery server has a "force from" option which by default is set to Always.
If you set it to never, then mailwizz will allow any email address in the from field of the emails, but this does not mean your smtp server will accept such thing, so it's up to your setup.
Otherwise, separate delivery server will do.