I know that all mails already have an inbox label applied, but I want the label exclusive of all my other filters.
I want to be able to keep track of all emails that will not otherwise be labeled so that I can simple click on the "other" label and delete them all at once or view them collectively. Deleting one at a time is a drag.
Best Answer
Filter
You can create a filter that will act on all messages that are not labeled by any of the filters listed above this one (filters are processed in the order listed). Just create a filter entering in the field "Has Text" the following:
has:nouserlabels
Potential issue: You have to make sure this filter is the last one on the list of filters. When I created it for the purpose of setting, it ended up near the bottom, but not the last one (to my surprise). Apparently, it's no longer guaranteed that the last created/edited filter will be listed at the end. (This used to be the case; see How can I reorder Gmail filters?)
And even if the filter is the last one now, sooner or later you'll add more and forget about that one.
Search
I think a better solution may be to bookmark the search link in:inbox has:nouserlabels which will bring up unlabeled messages in the inbox. There is a potential issue here too:
If this becomes an issue, you can temporarily turn off conversation view for this search; there is a switch on the first page of settings.
I wish there was a search parameter like
conversation:off
because it frequently makes sense to disable the conversation view specifically for the display of search results. Alas...