[SOLVED] Looping requests for favicon.ico and blank.ico

[Rich Graves]

A large percentage of the total requests to my server (6.0.4, tls_mode redirect) are for favicon.ico and blank.ico. This isn't presenting an operational problem for the server, but it sure seems wasteful, and is probably slowing down the clients.

[zimbra@mail2 ~]$ egrep -c '/zimbra/img/logo/blank.ico|/zimbra/img/logo/favicon.ico' /opt/zimbra/jetty/logs/access_log.2010-01-21
256791
[zimbra@mail2 ~]$ wc -l /opt/zimbra/jetty/logs/access_log.2010-01-21
898818 /opt/zimbra/jetty/logs/access_log.2010-01-21

They all seem to be Firefox browsers, versions ranging from 2.x to 3.5, both MacOS and Windows. All of the repetitive requests are over SSL. Lots of the requests seem to be getting 304 responses. Why?

[Rich Graves]

It's notification of new mail. Code 304 is "content not changed." Flapping between the two icons is what makes the tab flash.