In this case self-hosting is most definitely more secure. You won't get rekt by insiders leaking email lists if you're the only one that has access to it.

kevin

247bf84fda

bitcoin

Trezor email list compromised via mailchimp 

2big2fail

Helping people to use hard-to-link-to-physical-identity emails is better solution I think.

Self-hosted mailing system won't be any more secure than mailchimp, just smaller target.

I'm not against self-hosting. Big believer, especially for sovereignty reasons, but not security.