Better folder structure visualization and update

[sdejonghe]

Is your feature request related to a problem? Please describe.

Any update in the folder structure on the IMAP server is not reflected in the mail client. It require to remove and add the account again.

Describe the solution you'd like

If it is possible during the regular synchronization process between the IMAP server and the mail client to reflect any changes that occurs in the folder structure, it would be great.
One other feature for the clarity, is to present the folder structure in a tree view instead.
For example, I create a sub folder called level 4 in Thunderbird.

I check that the folder has been correctly synchronized on the server by checking the default email client provided by my provider:

But despite a refresh of the page or of the account, nothing is reflected on the mail client:

So it is only after removing and creating again the mail account, that it is possible to see the change

Also the fact that all folder are aligned on the same vertical line does not help to visualize the structure correctly which is really blocking.

Describe alternatives you've considered

No response

Additional context

No response

[ChristophWurst]

Any update in the folder structure on the IMAP server is not reflected in the mail client. It require to remove and add the account again.

Mailboxes are cached for 2h. You "just" need to wait. Readding the account is not necessary. The solution will be #5166.

Also the fact that all folder are aligned on the same vertical line does not help to visualize the structure correctly which is really blocking.

Confirmed. This must be a regression. #3147

[ChristophWurst]

It's caused by Calendar via https://github.com/nextcloud/calendar/blob/957c1b6782780631a74733ec17ebff3a57f2adfb/css/app-navigation.scss#L155:

This should be fixed with nextcloud/calendar@307a265.
@st3iny is this backportable?

[BiglifeMatt]

I second the need for the alignment of nested folders to be indented somewhat. That really helps with visual tracking of where the user is.

[ChristophWurst]

@BiglifeMatt please do the following

1. Disable Calendar
2. Open Mail
3. Take a screenshot of a mailbox with sub mailboxes
4. Re-enable Calendar
5. Post the screenshot

[st3iny]

@ChristophWurst Yes, my fix is backportable if it still relevant.

[BiglifeMatt]

Here is the screenshot without the calendar enabled. I while this is easier to read I am hoping we can continue to bump the sub-folders down the list as this is the view users are used to in most all other UIs.

[ChristophWurst]

Thanks. So the indentation is there 👍

[da-anda]

#8812 seems to be a duplicate to this ticket

[da-anda]

For me the issue still persists in 4.0.0 even with the calendar app disabled. See:

Klettern & Bouldern is actually a subfolder of Freizeit - but the indention is missing.

Expected result (after some custom hacking of the CSS) would be this: