This week I am mostly hating email programs that send out emails with the wrong charset listed in the Content-Type header.
The most common error I see is
Content-Type: text/plain; charset=iso-8859-1
When actually it should be
Content-Type: text/plain; charset=Windows-1252
If an email has the right charset then mutt will display it properly, but if it's wrong then I get a nasty mess and the mail is far harder to read.
It's therefore ironic that the worst offender is a regular email I get from a company who advises on small company PR