Mailpile Bold ttf is named Mailpile Normal

[generalmanager]

The name properties of the bold and normal weighted fonts are identical (Mailpile-Normal), making it impossible to install them on the same system without modification.

There are more inconsistencies tough:
Mailpile-Bold.ttf:
Font name: Mailpile-Normal
Family name: Mailpile Normal
Shown name: Mailpile Normal
Weight: Book

Mailpile-Light.ttf:
Font name: Mailpile-Light
Family name: Mailpile
Shown name: Mailpile Light
Weight: Book

Mailpile-Normal.ttf:
Font name: Mailpile-Normal
Family name: Mailpile Normal
Shown name: Mailpile Normal
Weight: Book

The strings above are all PS strings, the TTF properties aren't better tough.
This makes the fonts extremely buggy and fixing this should be trivial.