I use mailchimp but probably could get away with plain old email (I have about 45 subscribers). I just use the HTML editor that mailchimp provides and write some inline CSS. It's all "handcrafted" which is what I want. Hope this helps :)

I will say that their free tier (I think it's 10k emails per month?) is way more than enough for my use case. I'm not affiliated with mailchimp.