This seems to be a situation where setting up filters to check incoming mail and them move to desired folders. If you need more information, please respond with specifics. Thank you.

Tools > Message Filters Click on 'New' Create a filter with a meaningful name which auto moves new mail and manually to the desired folder. Save the filter Enable the filter.

Then switch on the Filter Log. Click on 'Filter Log' button Select the checkbox 'Enable the filter Log' click on top right X to close Filter Log window.

Check filter works by selecting the filter and setting it to 'Run selected filters on' and choose the 'Inbox'. click on 'Run Now' Any emails in Inbox that match the filter criteria should get moved to desired sub-folder. Info can be found in Filter Log.

There is a Help Article on using Message Filters. https://support.mozilla.org/en-US/kb/organize-your-messages-using-filters