(create a wiki account, and click 'edit') If you have a problem that is not listed here, please add it to the list so other users can benifit. Much of the information below is from users like you. Antivirus software can also cause odd behavior (bad, incorrect or unusual), and crashes (random or consistent, infrequent or frequent). This article is not just about performance issues. 9.2 Solution: Disable Windows System Proxies.9.1 Problem:Windows System Proxy blocking HTML images anecdote.9 Bogus Windows System Proxies Left by Malware.7.4.5 AVAST blocks images in HTML email.7.4.4 Avast Blocks Sending and Receiving.7.4.3 Avast 2015 causes invalid mail server certificate warnings sending/receiving mail.7.4.2 Hangs with 'Allow anti-virus clients to quarantine individual incoming messages'.7.4.1 Slowness and errors with nsemail.HTML.7 Configuration Notes and Solutions for specific Anti Virus products.5 Problem Antivirus and Anti-Malware Packages.4 Testing Suggests My Problem is Caused by Antivirus Software.2 My Problem Cannot be Caused by Antivirus.