Better handling of large spam mailboxes

Currently large spam boxes in Front are impossible to handle. Front has taken the view that users should not be allowed to mass-delete spam and must select each message (not ctrl-A) but for a spam box with 1000s of messages that isn't practical.

This could be solved by any of:

• Allow ctrl-A delete. Your users are grown-ups. Allow them to do what they want. All other email clients allow this that I know of

• When an email has been deleted on the server, delete it in Front. Then users could delete the spam on gmail and not still see it in Front

• Allow delete after time limit. Office365 and gmail both allow automatic deletion of spam after a delay. If it was labelled spam and I didn't search for it in 3 months then this was not an important message

If emails do get accidentally deleted after being spam-classified, the worst case scenario is that the email has to be sent again. It's fine to let your users do this.