A: There is a major increase in download time for the email, as you are sending a web page.
A simple 2 line email, can become no less than 10 lines worth of code, so when you use Html to send a newsletter or advert, you are increasing the size of that mail over five times. Then, if you add into that, images, it increases even more.
B: Html and scripts in emails are a target for viruses that grab on to the thing and hitch a ride.
There is no getting around this one, html emails are not secure, as many virus literally lay in wait for just the kind of scripting and the like such emails use, and hop right on for the ride ... right into your clients in box.
C: Accessibility issues, your Html email may not be amenable for font size changes etc. Cutting off those with visual Impairment's
Email is direct information, if you cut off your viewers from being able to view the email at whatever size font etc. they require for visibility, you have purposely cut your business off from some of your client base. With the current, graying of america, visual issues will increase, not decrease over time, so these factors must be taken into consideration.
D: Many email servers can not, or will not handle the Html email.
Plain fact, most email servers have been set up to consider Html emails as bulk mail or spam bait, with good reason, as all too often ... it is... so using this format is asking for your news letter to be thrashed.
E: Most mail filters will increase your spam rating for using Html, to the point were your viewer may never even see it.
Same thing here, if the mail makes it past the ISP mail server filter, its likely to be nabbed by the clients own email filter, which are in common use, and it will be branded as possible spam, and most often dumped, unread.
F: Many servers will break it down into both Html versions and text versions, which doubles the size of the email.
This speaks for itself.
A: What you see is what you get, always.
Html may or may not show up to the viewer, plain text always will
Other than a possible font mis match, in which case their email viewer will default to their own .. but, they will always be able to read it.
B: Mobile email readers, trying to figure out an Html email on your cell phone or palm top,is almost impossible, plain text however, not a problem
C. Accessibility, not a problem.
D: Any email server can handle text
E: Not likely to wind up in the spam box.
F: Only one version of the email, fast
Now those are just the basics, but the real reason not to use html for email is most people don't like them !
The main reason they don't like them, is that people can't seem to leave well enough alone. Most major companies see all that empty space and just have to fill it up with something, and that something is usually ads and other such garbage, that has nothing to do with the news letters content.
Dancing ad banners and other such stuff is all over the thing, it's bad enough to be presented with this kind of thing on web pages, but to get it as part of a news letter is just uncalled for. So, thanks to those who have over used an otherwise useful tool, the Html email, like so many otherwise good things, has become declasse meaning unusable. Then of course there is the spam angle, as spammers of all sorts have way over used this idea beyond the bounds of good taste, which is why most even legitimate Html email, is considered suspect.
Now, does this mean your news letters
have to be boring, no of course not, but by and large people want your
newsletter or advert, for one reason, updates and the latest news about
your product or services. Anything that is not that information, is window
dressing. If you want to offer an Html version, with all the bells and
whistles? Fine, give your viewer a choice, send them a plain text
email, and tell them click here for the Html version, that is up
on the web, where it belongs.