With Swift Mailer v3, each batch of 1000 emails would take approximately 30 seconds to send, utilizing about 10% of the server's CPU during the process.
I've since made the required changes to my script to use Swift Mailer v4. Everything about my script has stayed the same, with the exception of using the "LoadBalancedTransport" instead of v3's "Swift_Connection_Rotator", and a few other minor syntax changes. However, with v4, each batch of 1000 emails takes over 10 minutes to send, and uses 100% of the server's CPU (or as much as it can take) during processing. This is on a dual 3ghz xeon. That's quite a performance difference.
I've tried all the various transports to see if it was a problem there, but the result is the same. I'm assuming the delay in processing has to do with the new character encoding system (re: ticket #66?), and it seems the character encoding is done during each individual send regardless of a batch send or not (correct me if I'm wrong?).
Is there anything I can do in my script to help speed up the process? Are there differences in processing requirements for different character encoding types?
For now I've reverted back to v3 as v4 is just putting too much strain on my server for 50,000 emails/day. If there's anything I can do to speed up v4's performance please let me know. Much appreciated!
Matt