Hello Kais,
Thank you for the suggestion, and we will look into this. For the moment, I checked the Benchmark Email API documentation regarding the emailCreate() method and I see it can accept only one List ID or a Segment ID. It’s possible we can request Benchmark Email to add the capability to select more lists over the API, and implement that in a future version of the WP Plugin. It’s also possible to create multiple email campaigns – one copy sending to each list – and this could be done either behind the scenes or manually by repeating the form for each list. That last part is something you should be able to do at the present time, though I understand it may not be exactly what you are looking for. I’ll keep you posted. Thanks again for reaching out, and please let us know what else you come across.
Thank you,
Sean Conklin