On my Windows servers, we use HELM control panel with MailEnable. HELM do not limit mail box size in HELM. So users can use as much as they need, some users have over 1 GB junk mails in mail boxes. Find and delete them is lot of work.
Today i found a utility in that can delete old mails from MailEnable Postoffices.
This utility allows you to purge old mail messages from the message store. It can be scheduled as a batch job to clean Deleted Items folders, Inboxes, etc for each postoffice.
There are many more tools available at
To delete all mails that are 400 days old
Following command will delete all 400 days OLD mails
mepurge ALL 400 INBOX+DELETED+SEND
To delete all mails that are 100 days old from postoffice bizhat.com
mepurge bizhat.com 100 INBOX+DELETED+SEND