Get all server tags button
It would be useful if Preferences->Mail Preferences->Label will get some button added, [Get all labels from servers].
Background: "Server tags" is the element stored on the server per folder. "Labels" in Evolution is the mapping from "server tags" to named "Labels" with a color.
Currently, the used server tags can be seen in the folder context menu Properties->Labels.
Starting to configure a new Evolution, let's say connecting to 10 servers with 10 folders each you need to ask every folder for the used server tags in order to add an Evolution label for it. Moreover having several Evolution installations, it's hard to keep all client configurations in sync. As for the syncing I'm going to maintain a script as workaround to merge
gsettings get org.gnome.evolution.mail labels
and
gsettings set org.gnome.evolution.mail labels ...
while Evolution is stopped. Currently there is no way to sync the Evolution Label configuration on the server.
For the expensive operation of fetching all tags from all accounts in all folders, it would be at least useful for now to have a button on the main Preferences Label tab [Get all labels from servers]. The dialog UI could be the same like used in the Label tab for a folder, just populated from all servers/folders + a column of the origin account maybe. It would add all found tags with a default color (no color) and a name equal to the server tag for the option to rename it later. The expensive search progress should have a Cancel button.
Right now I'm not sure why it's useful to have a tag to label mapping. Why not having tags always equal to the label? Is it just for adding a "I_mportant" shortcut option?