[CentOS] Slightly OT : newsletters, mail formatting and netiquette

Hi,

This question is not exactly CentOS-related strictly speaking, but here goes. I'm running a few newsletter servers for myself and a handful of clients on public CentOS servers with PHPList.

For the last twenty years or so I've followed the basic rule that mails should have no formatting whatsoever, only simple text. And now I wonder if that basic rule of netiquette also applies to newsletters.

I'm a subscriber to a series of tech-related newsletters, and I couldn't help but notice that they all seem to be HTML-formatted, even those from respectable hardcore geek groups.

So my somewhat naive question: is HTML formatting acceptable in newsletters?

Cheers,

Niki