Q : How do add more than one campaign to Email/Newsletter zone ?

A : Our OpenX having more restriction on this type of zone .

• You cannot link a campaign to an email zone; you must link directly to a single banner.
• No Cookie Image Tag is the only ad tag that can be used in these zones .So you cannot rotate ads in this type of  zone .
• You couldn’t link HTML banner type .

If you have only one banner with that Email zone ,then does redirect to destination URL of banner . But if you add more banners to that zone then it remains on empty blank page.

But we can link more than one campaign with  banner to that zone .But should that campaign’s active period shouldn’t overlap with  other campaign’s active period.That mean while banner deliver time only one campaign only active in that zone.Else you can set Time targeting for individual banners and this Targeting also not over lap with other banner’s targeting time.