Can I force html with every email?

[RodG]

The problem I have is that for the first year the default was set to text.

Irrelevant.

Many of my customers have complained the emails are being sent in txt format

With respect, I find this difficult to believe.

, and they are too lazy to switch it.

They've told you that have they?
Again, I find this difficult to believe, but even if it were true it is no reason to inflict HTML on those that had opted for text only.

Why should I suffer because you have one or two 'lazy' customers?

So I was hoping for a solution where I can switch it for them for certain promotions that go out.

I've also know from personal experience that ugly text emails get deleted immediately.

And I know from experience that (with few whitelisted exceptions) any HTML emails I recieve get forwarded direclty into my spam folder, never to be seen.

Is that what you really want.

I am the opposite as you,

Obviously.

I am one of the 'strange' people that believe Web pages were designed for HTML and Email was designed to be text based.

Strange thing is, the RFC's (you know about them right?) actually back up my beliefs.

HTML emails are little more than a 'kludge' that has ended up being responsible for the transmission of 99% of the viruses floating around. Without HTML emails it is impossible for a virus to spread in this manner (which is why I send them straight to the junk folder).

and so are most of my customers.

You said it, so it must be true eh?

Emails that get sent in txt are are deleted immediately and are not even read.

Not in this household, and not with any of my students either.
I teach the safe networking practices.

I wonder how many users actually prefer text and not html?

All of the smart ones :)

Most modern browsers support html

Errr, I think you'll find that every browser ever written supports HTML, on account of the fact that HTML would be pointless otherwise

the age of text based email has long gone.

Yes, and we have flying cars, man has landed on Mars, and Skynet is about to take over the world.

You won't like this, but please do a little bit of research as to how Email actually works at the network layer. In spite of being over 30 years old, it is still primarily a text based system (and by text based I mean it only uses 7 bit data (127 different characters). I'll leave it up to you to determine how it manages 8bit data and/or HTML.

Cheers
Rod