E-mail missing

Hi,

Recently, I found that some emails are missing.
Could anyone tell me does it caused by Avast IS (Email protection / Antispam function)?

http://social.answers.microsoft.com/Forums/en-US/xpnetwork/thread/8211fd25-d364-4fd9-920e-f2d36618d98f

Is it possible to turn off email protection and get risk of trojens attack ?

I am using WLM as email client to receive POP3 accounts only.

Thanks