The question is one of different opinion, the basics are that plain text emails are more likely to reach inboxes as HTML rate higher by SPAM filters but a good looking HTML creative can convert more, so you have to weigh up deliverability versus design, you can argue both sides, what’s the point of sending out a great looking email if no one is going to receive it but what’s the point of sending out a plain text only email if it’s just deleted because it lacks the creative pull, a difficult choice.
Someone with a very creative mind will argue until the end of the world that their emails have to be HTML and look the biz, I have had many conversations with clients who think this way, I then have to explain to them after the mailing why the stats wasn’t as expected.
Also take into account that some large corporates stop HTML emails server side!
A few suggestions
1) If you are going to send HTML, make sure to also send a text only version (multi-part) or as I do for some of our managed sends, I will send a HTML version first and then a couple of days later send a plain text only email, so in theory some subscribers who’s HTML email was rejected server side as it contained images or was put straight into their junk box might receive the text version.
2) Always have a link at the bottom of the email to a webpage version of the email, Newsletter Sender can do this automatically.
3) Give your subscribers the option of receiving a text or HTML email from you, this can be done via the webpage newsletter signup function.
4) Limit the amount of images and links within your HTML design, the more you have the higher the spam rating.
5) Try a happy medium and send a text only HTML email, you can then use formatting and will receive a better spam score as you wont have images.
Hope this helps you decide which is better for your marketing campaign.
