Core

• Bump Mailman to 3.3.3

Web

• Bump Postorius to 1.3.4
• Bump Hyperkitty to 1.3.4
• Bump Django-mailman3 to 1.3.5
• Fix a typo in uWSGI configuration that resulted in 1 process instead of 4 in config (#428)
• Fix a bug where Core couldn’t fetch list’s welcome template from Postorius when subscribing a user (#368)

Postorius

• Bump Postorius to 1.3.4
• Same fixes for uWSGI config as Web image. (#429)
• Same fixes for templates as Web image. (#368)