Feat: Allow user to set fields to be searched by default from search box.

[mandusm]

Is your feature request related to a problem? Please describe. When searching, you have to either type text= or use the advanced search box to search for text inside the email body.

Describe the solution you'd like I would like to be able to select the text search fields available in the advanced search, and set them as "default", so that when I type a search, it will by default search for the value I entered in all the saved fields. This is similar to how RoundCube search works.

Describe alternatives you've considered None

Additional context I do plan on working on this feature myself when I have time. Specifically time to get my head around the codebase, but I would like to see others' interest in this and maybe some better ideas.

[edlerd]

Searching on any field in any folder as an optional default would also be nice. Like in gmail.

Currently, only a single folder can be searched.