I'm really puzzled why the designer chose to open some specific areas here. Specifically, the letters "m" and "p" in Chimp.

Cursive script has some "tight" areas for a reason. For example, the first and second vertical strokes of the lowercase "m" are supposed to overlap to form the appearance of a single stroke. The break for the curve should not start at half of the x-height. Likewise for the lowercase "p", the break for the curve should not start so low.

The net result is reduced readability, IMO.

I actually didn't see it like that. But now that you pointed it out, I can't unsee it.

I saw exactly the same thing. The older logo was definitely clearer in that area.

The loop on the P is definitely decreasing legibility at small sizes.

I was kind of wondering if it was 'y', 'js' or 'p'. The 'p' of the older logo was more readable in my opinion.

Overall, I like the new logo more.

I agree, my eye went RIGHT to the "y" at the end - but it's not supposed to be a "y".

I keep reading MailChimy

Was MailChings for me, admittedly with an odd "g", but this part is definitely worse than before.

I saw Mail Chimyo but now I see MailChinys as well. The one thing I don't see is MailChimp.

Can't unsee. The new p shape does make it less readable.

It really starts to look like a y in the smaller size.