Managing your email attachments in Apple Mail

Step 1. Open the message with the attachment:

Then click on the 'save' button in the message headers, next to attachment line:

You can choose between save all attachments or save individually (this example has only a single attachment):

You will be prompted for the download/save location. If you need to access the attachment from multiple machines, ensure that this location is a network drive.

Step 2. Then go to the Message menu, and click on 'Remove attachment'. A copy of the original email, minus the attachment, will be created on Hermes (you can check this via webmail) and the original message with attachment will be marked for deletion.

Step 3. You now have to actually delete/expunge the original message with the attachment in order to reclaim the filespace on Hermes. To do this, go to the Mailbox menu and choose 'Erase deleted messages', or to the Trash in the LH pane and choose 'Erase deleted messages'. Sanity-check via webmail if required.

Steps 2 and 3 can be carried out on a large number of messages if you highlight them in the top RH pane, then choose Message menu, remove attachment (step 2) followed by Mailbox menu, erase deleted messages (step 3).