DeskPRO will automatically delete mail from your POP3 server after it has been successfully downloaded and saved. (The "Keep Messages" setting available in earlier versions of DeskPRO is no longer available).
Keep copies of POP3 mail using forwarding
If you want to keep mail messages that have been processed by DeskPRO, set up mail forwarding to a second separate mailbox that isn't used by DeskPRO.
For example, configure email@example.com to forward a copy of incoming mail to firstname.lastname@example.org. Since you do not have a ticket account monitoring the archive address, messages will never be processed/deleted from it and there will always be a permanant copy.
To find out how to set this up, consult the documentation for your email server/provider.
Use IMAP instead
If you want more control over how mail is processed, we recommend you use an IMAP account. If you're using DeskPRO Download, make sure you have installed and enabled the php5-imap PHP extension which is required for IMAP support.
Unlike POP3, the IMAP mail protocol keeps track of which messages have been read. You have more options in terms of how messages are handled:
If you want to keep an archive of all messages that can be accessed from outside DeskPRO, you should use the Read all messages and then move option.