I use multiple list, with the same customer on different list (list #1 for commercial proposal, list #2 for information).
I configured the unsubscribe settings on "Only unsubscribe them from this list".
When I send a campaign, the addresses which hard bounce on list #1 are added to the Suppression List.
But if I send another campaign to list #2 (with the same addresses) the bounce addresses from list #1 are used again in this new campaign.
I've the same problem if I manually add addresses on the Suppression List; if the addresses exist in one of the list, the addresse is used on the campaign.
This is happening because you have the "Only unsubscribe them from this list" option selected in your unsubscribe settings. To keep this from happening again, you can either change the setting back to the recommended option to unsubscribe them from all lists, or you can place all the recipients in the same list with segments based on the purposes for which you would email them (the multiple option custom field would work nicely). See this page on how to create and use segments - http://help.campaignmonitor.com/topic.aspx?t=90 .
Thanx for your quick answer.
I used different list to give the opportunity to the customer to unsubscribe to one of the list, and stay subscribed to the other.