10% of the emails are undeliverable.
I am using mandrill and it seems to put the emails on rejection list, however is it possible to set it up so that the subscribers will be deleted in mailwizz lists.
If those subscribers bounce back, they are added into the blacklist where they are kept for X days and then they are removed.
X days mean your settings from Backend -> Settings -> Cron -> Blacklisted days
A value of around 7 days should be okay there.