If you're asking if there is a problem, well, no, not really. It appears that the e-mail you received is displaying as an HTML file. And, you must have the font size enlarged for displaying your e-mail. So, what you're seeing is the app's attempt to enlarge the "web page" font within the confines of the Mail app's borders. So, the font is going to blend together. It's the same affect you would see on a computer if there wasn't enough room for the page to load/spread out.
There's only one fix for this - decrease the size of your viewing font for Mail. To change it, go to the General tab of your Settings app and then tap on the Accessibility tab. Scroll down the right side until you come to a line titled "Large Text." Then, either toggle it off, or lower the size of your font.
Again, this is a normal function of the Mail app - it tries to scale according to the size you've set. If this doesn't happen with many emails, I'd suggest just leaving it be (assuming you like the size of the font in your Mail app when not viewing HTML mail).
Hope this clarifies.
Or it could just be poorly designed HTML/CSS. Happens, especially with web designers who only target one or two popular desktop browsers.
Fortunately, it's far less common these days than it used to be.
Great info for a Technically Challenged Old Guy. THANKS