How can I change settings for yahoo email 'trash' so the messages aren't deleted after 24 hrs?

...trying to keep some 'recently deleted' emails longer than 24 hrs, but Yahoo has a setting to delete that I cannot find where to make changes. Any help is greatly appreciated, thanks!How can I change settings for yahoo email 'trash' so the messages aren't deleted after 24 hrs?
The trash bin is one that we can't do anything about. There is a message on it when you delete telling you that items sent to the trash are just held temporarily, Yahoo empties at random. Sometimes everyday, sometimes 3 days to 1 week. You can put things into folders and give it a name, then delete them at a later time when you are sure you don't need them.How can I change settings for yahoo email 'trash' so the messages aren't deleted after 24 hrs?
I don't know that you can change the trash setting. Why can't you just keep the emails, rather than putting them in the trash? You can make different folders if you don't want to keep them in the inbox.
go to mail options in the upper right corner- mail options- then spam settings