We are doing Bulk email campaign in our environment. We have legitimate domain and IP. We are trying to send emails with scheduled basis. We have started the campaign from 12AM mid nite. After some time system is not generating any emails between 6AM to 9AM. That time we scheduled some mailing list to send out. After 9AM other email lists are able to create and send out emails. Is there any cronjob running on that time or is there any default configuration causing the issue?
If some one faced these kind of issue, please kindly send me the information, it will help us to arrest the issue.