Test mail headers

I'm working on a custom ecommerce system that's sending out a lot of emai开发者_如何学JAVAls. These emails are formatted nicely using HTML. However sometimes I have customers complaining that what they receive is "nonsense". Basically they can’t view HTML.

What can I do to ensure that the customers always see the same result? Is there some kind of service that can test the headers / coding in the emails to ensure its optimized correct?

Thanks in advance

What can I do to ensure that the customers always see the same result?

Send a text email with a link to a web page with more information.

Some companies lock their email systems to text only email, and there's not much you or your customers can do about it.

Smart phones generally do better with short text email.

It happens, it's normal!

We're using this solution: our user can choose if they want to receive plaintext or html emails. They just check the one they like, they try, if they receive nonsense, they change into the other option. From the next email, everything will be fine (we hope).

Just provide them both ways of receiving emails, and bind the choice to their account. Everytime you send, you check on the type they chose and... you send :)