Perhaps it's a virus scan issue?
We don't always work well with some virus checkers. We have wikis on that subject. Here is an excerpt:
Virus scanners can significantly slow down ZCO performance. NOD32 has been identified as not working well with Outlook 2007. AVG is a known culprit, particularly version 8. In many cases these scanners can render HTML E-mail as plain text. AVG’s certification feature appends text to mail messages, sometimes causing these messages to lose HTML formatting. To disable this, go into AVG’s Advanced Settings, and under E-mail Options, uncheck the box that deals with Certification of Incoming E-mail. Sometimes virus scanners render emails completely blank.
Many anti-virus users disable E-mail scanning, since Zimbra does it for you. To disable the E-mail scanner in AVG, open the Control Center, select the E-mail scanner plug-in, click Properties, click on the Disable Plugin button, and check Ignore Plugin Condition. |