Very Impressive Pradeep, Well Done Sir! Would you mind please to kindly enlighten us on particular mailwizz settings and what was modified to increase sending limits that high? - what is the biggest bottleneck in mailwizz? - are there features/standard configurations that can be turned off to increase send? - settings/customers/campaigns >subscribers at once - settings/cron > delivery settings (including PCNTL settings) - php version - where mailwizz files modified? - settings/delivery servers > pickup directory? local directory? - why/how so many delivery servers? - are other extensions used? if so, which ones? - is mailwizz dumping flat files into the pickup directory for pmta? if so, at what rate?