Blurry images usually means the size selected in the plugin’s option page is too small… have you tried increasing it to Large, or using “Full”, which is the original full size unaltered? If still blurry using Full, then the original image size uploaded is too small, upload a larger image. Also, be sure you have the “Resize images” checkbox unchecked on the RSS feed page (in Mailchimp, and maybe other services as well.)
The other option is to use some custom CSS to display the image(s) smaller in the email, max width should always be 600px for Mailchimp, so make sure your images are at least that large, and ideally exactly that width, with a reasonable height (300-500px typically).
For your feed, I’m seeing the images being added to the feed without https:// or https://, they are using “//” which is a relative protocol that works on websites, but not in RSS. It needs to be absolute for it to work best. Here is the URL it’s showing in your raw feed:
“//252366-784522-raikfcquaxqncofqfm.stackpathdns.com/wp-content/uploads/2014/04/uttapam-1-of-2-e1588291276485.jpg”
There’s a plugin or the CDN itself changing the image URLs to be relative, turn this off and your images should display ok.
Let me know if you need additional help on this.