Hello. I would like to ask about iOS stock mail app. First of all I have been using iPhone and iPad with one iCloud email account. I have noticed that if I have deleted email with attachment, mail app storage at settings/general/usage doesn't reduce. It keeps growing and I can't decrease it. I have deleted all emails and on iPhone mail app size is 50MB and on iPad 6MB. After restore they were about equal size- 3.8MB. However now on iPad mail app takes more storage 
Both runs on latest iOS 7.1.2. Noticed this issue from iOS 7
Both runs on latest iOS 7.1.2. Noticed this issue from iOS 7