If you are talking about webmail, just drag and drop the mail to whatever folder you want to put it in.
The inbox is for new mail and there's no way to move read mail to a new folder in one click. Why doesn't BT let me decide how often to empty the trash (or set it to a reasonable time) like every other email I've ever used? Looks like it's time to migrate all my email to another provider.
If the inbox is for new mail, what do you think the trash box is for? To move an email to an new folder does unfortunatly take two clicks once the email is open. You need to click on the "move to folder" icon and scroll down to the folder you want to move it to and click again but if you do as licquorice suggested it can be accomplished in one click.
If you do it from the Inbox rather than an open mail, you can select as many as you want and move them all in one go.
My mum uses pop, so emails are downloaded to email client and in webmail items downloaded are immediately moved to trash. This is no issue. However, the Trash empties so fast that if she has lost an email it is not retrievable because TRash empties automatically without leaving any time to get it out of Trash. It should not empty so fast. A week would be acceptable, less than a couple of days is not user friendly. What is the point of even having a Trash folder if peoploe do not have the opportunity to retrieve emails, it may as well not exist.
I thought it used to wait a month but was very supprised to see that users do not get so long. Mum downloaded on Tuesday afternoon and by Thursday morning it was emptied.
So how do I set it up to wait for a week and then auto empty?
Mail is only lost if it is deleted from the client, if it has been deleted it is no longer required. The whole concept of moving mail into a trash folder once downloaded to a client is completely wrong in my opinion and has only fairly recently been introduced by BT. The POP3 protocol downloads mail and then issues a DELE command which, in my view, should delete the mail completely from the server. The whole reason I use a client is because I do not want any mail to be stored on a possibly insecure server for any longer than is necessary.
A simple solution for your mother would be for her to create a Deleted Items/Trash folder on her mail client and move potentially unwanted items to there instead of deleting. This folder can then be reviewed and emptied manually periodically as required.
Edit: As I always use shift/delete to permanently delete items, I forgot that just deleting an item will move it to the deleted folder in the client anyway. Don't know which client your mother is using, but Outlook 2010, Thunderbird and Windows Live Mail all do it. So there is no reason for her to lose any mails.
If you go into your email clients settings you should be able to tick the box "leave on server". This will do just that and if you also tick the box "Remove from server" and set the number of days that you want them to remain on the server until deleted.
This will keep them on the server until the allotted number of days have passed then they will be deleted.