Exchange Remote Connectivity Analyzer
OCS Remote Connectivity Analyzer
POPGrabber (Free Tool with collect pop3 email and delivers them to another server via SMTP.
POP3 Grabber Works With Exchange 2003/2007/Exchange2010 and free version is limited 3 popaccounts)
POPcon (A Tool with collect pop3 email and delivers them to another server via SMTP.
POPcon Works With Exchange 2003/2007/Exchange2010)
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