There is some spacing padding and unit which causes order summary totals misaligned.
https://github.com/nopSolutions/nopCommerce/blob/1dc1febc84890fa976282e6da16a1824239d159c/src/Libraries/Nop.Services/Messages/MessageTokenProvider.cs#L765

0.6em 0.4 em
should actually be 
0.6em 0.4em
.

This happens in many places in that method. This is important because it's not possible to change structure of this table anywhere else and this misalignment will look weird in emails.