I am trying to fix the delivery speed of a customer’s Newsletter plugin (non pro version).
We are running WHM/cPanel 56, with Exim Mail as the MTA
The user is setup to authenticate to a username and password within their domain name
Wordpress v is 4.4.3 (will be updating this soon since 4.5 is out)
Newsletter plugin is 4.0.9 (there aren’t any changes in the updated versions other than some security fixes that show they would improve the delivery engine)
We have implemented the following from your support documentation:
1. Added a Cron job to cPanel to run every 5 minutes to send an email
2. Removed any Resource Limit checks from the cPanel user
3. Increased the maximum hourly limit within the plugin to 300
4. PHP Time Limit server wide has been increased
5. We aren’t limiting their max hourly messages in any way shape or form
We originally had the site running behind Mailchannels and on another cPanel server (still running the same version, just PHP was configured slightly differently on that server). We have the customer currently on PHP v5.6, with Mailchannels for this customer disabled. The site took 3 days to send out 2400 emails via our servers. I disabled outbound spam filtering for that email address since 1) It’s only ever used by the customer to send this newsletter, 2) The emails are definitely not spam, and 3) it’s not really necessary introducing something in the mix to slow down the mail from sending.
The plugin itself is great and has loads of ways for me to test sending messages but when my customer’s subscriptions take 2-3 days to send out it makes us look bad since in the beginning it would take no more than a few hours to send out 1000 emails.
If you need anything from me in terms of logs, or settings that I haven’t included here please let me know and I’ll be more than happy to get that posted here.