search for: dbox_attachment_min_size

...at the MIME part isn't multipart/* (because then its child parts would contain attachments). Plugins can also override this. For example they could try to determine if the commonly used clients/webmail always downloads and shows the MIME part when opening the mail (text/*, inline images, etc). dbox_attachment_min_size specifies the minimum MIME part size that can be saved as an attachment. Anything smaller than that will be stored normally. While reading a potential attachment MIME part body, it's first buffered into memory until the min. size is reached. After that the attachment file is actually created an...