Rinoa21,
I also use the Whole Disk Encryption (WDE) feature of Symantec Encryption Desktop.
At the moment, I cannot recieve any email through my POP3 email service provider, Earthlink. I also created a GMAIL account, set it to use POP3, and duplicated the problem -- I cannot connect and receive POP email through either Earthlink or GMAIL.
Curiously, sending mail via these POP/SMTP email service providers is working fine as long as I create the correct service definitions for SED messaging -- specifically, the default inbound and outbound servers that SED defines were not correct. For both Earthlink and GMAIL, the outbound server is different from the inbound server. The SED default was to define the same for both inbound and outbound. I simply adjusted the SED service definitions to align with the correct/different inbound/outbound servers and now I can send outbound POP/SMTP email in the clear through either Earthlink or GMAIL
So, on-going trouble-shooting is focusing on inbound. If I simply uninstall Norton 360 then inbound works fine (for both Earthlink and GMAIL). Like you I need the email protection in Norton 360 and cannot simply disable it to get email working. Similarly, I need the messaging encryption feature of SED, although quite infrequently.