OneCare should have no effect on any email program's ability to send/receive email. However, if you had other security software prior to OneCare and it was not removed completely, this can happen, especially if that software had provided email scanning. Many of the security vendors provide a cleanup tool:
Norton Removal Tool - ftp://ftp.symantec.com/public/english_us_canada/removal_tools/Norton_Removal_Tool.exe
McAfee Removal Tool - http://www.majorgeeks.com/McAfee_Consumer_Product_Removal_Tool_d5420.html
If you continue to have the problem, please contact support.
How to reach support (FAQ) - http://social.microsoft.com/Forums/en-US/onecareinstallandactivate/thread/30400b52-7f26-4ba0-bc18-17e305329d90
-steve
Microsoft MVP Windows Live / Windows Live OneCare & Live Mesh Forum Moderator
