Urgent: can somebody tell me how i can send my mailcampaign (total 1800 contacts) in batches of say 500 per hour??
Hi ConnactOnline, welcome to our Forum!
Thanks for posting here.
You can send your campaign to all your contacts if they are active, meaning in one single list in your account.
If you are starting now with ActiveCampaign, we would just advise you to warm up your account before sending your communication to all your contacts in one go. Here’s an article about deliverability in your first 30 days. Hope this helps! 
Well, you can Tag each contact with the Campaign Splits, and then use same to filter out while Campaign sending. Hope it works for you.