Conversation-based list model

[charlag]

As a user I want to see a single (latest) email per conversation in the mail list so that I have a better overview.

AC

• Only the most recent mail in the current folder/for the current label is shown in the list
• Sent folder and search display individual emails even if conversation mode is enabled
• When opened it will open that mail from the conversation
• It should be possible to configure if mail list displays conversations or mails
• When filtering the conversation should match if one of the mails we already loaded matches

Tasks

• New list model
• Think about URL <-> list interactions (e.g. URL that points to an older email in the conversation should select the conversation)
• New preference for displaying conversations/mails and persistence for it

Estimated: 24h