Describe the bug
Since yesterday (12th of may) my prospect-mail fails to start up. It just hangs at the "opening the envelope" animation.

To Reproduce
Steps to reproduce the behavior:

1. Start prospect-mail
2. Wait for it to fully load
3. Wait forever...

Expected behavior
A normal startup.

Desktop (please complete the following information):

• OS: Ubuntu 20.04
• Installation source: snap
• Version 0.5.4 (ie. stable)

Additional context
FYI, using a browser to open my mailbox works fine.