Mail taking up 2.5gb of iCloud storage even tho I've deleted most of them

Hi

According to my iCloud settings, Mail is taking up 2.5gb of my storage. But I deleted most of my email from iCloud and moved important messages to my laptop. Yet there has been no change in the amount of storage being used by my emails. Most of them are just text mails and don't have large attachments or photos etc. This is driving me nuts. Does anyone have a solution?

thanks!

WG