Hi,
Acymailing needs to render each mail, send it and register the sending in the database. That takes time and given your info you're limted to 80 seconds per batch and you're able to send 150 mails within that timeframe.
Probably you also need to send out confirmation mails, welcome mails and maybe you have also automations running that send out mail every now and then. Check how many of these you send on average and then lower the number of mails per batch down to whatever suits you. Like lowering to 140 or 130 per batch. This way you'll leave some margin to also send out these other mails on time.
When you're using manual sending set it to send to 140 mails per batch and wait one minute for the next batch. This results in app. 2.500 mails per hour.
If you want to keep using the automatic sending you're limited by the cron service. The default cron in Acymailing is a cron task running on Acyba's server and it's limited to be set once every 15 minutes. You can disable the cron task on Acyba's server and switch to a different cron service. Eiother on your own server or any thrid party cron service.
When you choose to use a different cron server, select one that allows you to run a task every two minutes. In your Acymailing you also need to set the automatic sending to 150 mails every two minutes. This will result in a sending rate of app. 4.500 mails per hour. Assuming you do not run into other limitations.
One of these other limitations could be the time the cron server is waiting for Acymailing to complete the job. If that time is shorter than your 80 seconds your batch is running Acymailing will stop sending. The next time Acymailing is triggered by the cron it will only send out the remaining mails. Until the queue is empty and only after that the next time Acymailing is triggered it will start sending a new batch. So if you don't have everything right, you might considerably decrease you're sending rate.
