Smart quotes aren't encoded properly in Mailman non-digest emails

Symptoms

Emails received from a mailing list contain an improperly encoded character.

- Double quotes appear as: "=E2=80=9C" and "=E2=80=9D"
- Single quotes appear as: "=E2=80=98" and "=E2=80=99"

Description

Some mail programs enable smart quotes by default. When sending emails containing smart quotes, the email that is received by mailing list users contains the wrong format for the quotes.

We've opened an internal case for our development team to investigate this further. For reference, the case number is CPANEL-47499. Follow this article to receive an email notification when a solution is published in the product. 

Workaround

Disable smart quotes when sending emails to mailing lists.