The usage of ALT text is quite important not only in web design, but in email design as well. The more images you use the more incomprehensible your email will be, as your subscribers will have no idea what you are talking about, what are you trying to sell, what is your CTA.
I received an email the other day and gmail had turned off the images. And I saw what you see in the screenshot below:
Can you guess from which company I received this email?
No?
Well, neither can I! How can you name your logo the same as the filename? You spent time styling it, why not some extra effort to replace 8 characters.
This is definitely something you should never do.