We used to store files as base64 strings in Postgres, but not anymore | The Official MailPace Blog

Email attachments are always encoded into base64 for sending, so our API specifically asks for that as the input format. Yes, there are a million better formats for encoding binary data/images, but hey, SMTP is older than the internet, and attachments were hacked on as MIME types in the mid-90s, so here we are.P.S. If someone at Google, Microsoft or some other big email giant is reading this and wants to add support to SMTP for e.g. brotli encoded data, please do, and we’ll add support for it.