I was forced to move my site behind Cloudflare. And now when I process the queue (it is only 110 long) it stalls out at Stage 5 and says the server may be too busy. I put a skip rule into Cloudflare for everything the AI recommended but it still won’t get passed. The AI eventually responded that Cloudflare is killing the connection before it finishes. And the only work around is to send phpLIST to its own subdomain and grey cloud it. Does that make sense?
Actually figured this out. If you get put behind Cloudflare, make sure the mail DNS mail.yourdomain.com is replicated in the phpLIST config. Cloudflare is not forgiving and smpt.yourdomain.com will no longer just work.