If you need to export contacts from multiple contact lists the default interface of Interspire allows for that. Via the Export Contacts menu you can select as many lists as you want. There are a few things that are not very intuitive.
First, if you have contacts that are on more than one of your selected lists they will be exported twice. The estimated number and actual number of exported contacts shown in Interspire Email Marketer will be based off of that duplication and will therefore be potentially inflated from the actual number of unique contacts.
Second, if you want to filter your export by any specific data that will be a challenge unless all your lists have the same custom fields. You will only be able to filter by fields that are shared universally by all the lists. Its makes sense when you think about it. That said, if you export fully without any filter it is very easy in the exported file to filter based on content and fields. All data from all fields from all lists will be exported.
If you are trying to build a new master list that consists of all the contacts from several other lists this is likely the best method to approach that. Export contacts from all the desired lists and then import them into the new list. Interspire will automatically account for any duplicates. With our “Exclude on Send and Import” product you can also dedupe the import file against any current existing list.