I can add info to this behavior:
It is not restricted to plain-text mode - also occurs in html.
The inconvenience is that it become impossible to split lines in the
quote, say, to insert a reply.
The workaround is to copy the text inside the format box and then past-
as-quotation to the end - th
Just for fun, I had the same thing - except it was persistent until clicked.
Checking, I found:
$ gconftool-2 -R /apps/evolution/mail/notification
notification = true
blink-status-icon = true
So I did:
$ gconftool-2 -s /apps/evolution/mail/notification/notification -t bool false
$ gconftool-2