I recently moved my site from CF7 to CF9. We normally send out several bulk emails and newsletters in the 20,000 - 50,000 message range. I send these emails in chunks of around 500 messages at a time and then wait for the spool directory to have less than 50 messages before sending another chunk. This has worked great for us for several years but now with the move to CF9 the messages are leaving the spool directory very slowly. It seems to process one message every 1 to 2 seconds. A list of 40,000 emails would in the past take say 8 hours is now taking 30 + hours to go out.
Here are things that I have already looked into:
Running Symantec Endpoint Protection and have set a rule up to exclude the CF Mail directory as well as it's child directories. I had to make the same change on my old server as the AV scanning was slowing the process tremendously.
When running CF7 I was using a smtp server on the same machine, but now the smtp server is a different machine on the same network. This should not cause these issues and the smtp server is not bogged down or having issues.
Has anyone else run into these issues with cfmail on CF9? How many messages should leave the spool on each interval? I know on my CF7 server it did not send only 1 message per interval, why might this be the case on CF9? Any help or insight on this issue would be greatly appreciated as I desperately need to solve this issue.