Hello,
Here's a link to the official corresponding Symantec article: Many Unexpected Pop-Ups from Symantec Email Proxy are Displayed
Is your system infected? Symantec tools to help clear an infection
https://www-secure.symantec.com/connect/forums/your-system-infected-symantec-tools-help-clear-infection
There have been a couple of good forum threads about that error message:
https://www-secure.symantec.com/connect/forums/problems-sending-message-outlook-2003-and-symantec-endpoint-protection-11
https://www-secure.symantec.com/connect/forums/how-do-i-prevent-endpoint-protection-blocking-outbound-emails-large-groups-people
https://www-secure.symantec.com/connect/forums/im-using-endpoint-last-week-i-have-see-msg
As a Workaround, try these steps -
- go to add remove program
- Select Symantec Endpoint protection , click Change and then Modify
- Uncheck Anti Virus Email Protection and install.
That Email Protection only examines messages for threats (worms, viruses, etc). It does not scan for spam: there are other products which provide that protection (Symantec Mail Security for MS Exchange). As far as I am aware it wouldn't be responsible for sending mails like the ones you have added to this forum thread.
All the same, I recommend that, as a best practice, steps are made to ensure that all clients are runnig the latest releases of SEP or SAV, have up-to-date definitions, and all MS patches are applied.
Hope that helps!!