Was going to suggest this alternative service but the founder beat me to it. Their support team is quite fast and helpful. Ping them on chat when I was having troubles setting up in the beginning, and they literally got back to me within a couple of minutes.
Yes, we support DKIM signing when using our SMTP for sending out email. We generate a pair of public/privatekey and ask you to set public key as a TXT record on your domain.
This would save me tons of time scrolling the web. But would you consider integrating this with Telegram or Slack? Would be nice to have a message on Telegram or Slack every Monday.