I only have a few mail messages. It isn't the number of messages or files, it's the total size. You may have one or two very large messages which are filling your space. Neither PIne or Mail can read these programs and attachments directly. This command deletes all but the current version of all files.
Subdirectories are very useful.
Then you can use delete to delete files, etc. You print and use these instructions to set up a dial up network connection. You can also use Netscape, Eudora, or Internet Explorer to read your mail. Be aware that these programs can only read new, unread mail, and cannot be used to access any other files in other folders. VMS has help for its own commands and most other programs.