diff --git a/src/doc/user/usermanual.xml b/src/doc/user/usermanual.xml
index 1507a6d4..fc32b08d 100644
--- a/src/doc/user/usermanual.xml
+++ b/src/doc/user/usermanual.xml
@@ -6158,7 +6158,13 @@ mondelaypatterns = *.log:20 "this one has spaces*:10"
tbird flag is defined, and it should be set
for directories which hold
Thunderbird data, as their folder
- format is weird.
+ format is weird. Example:
+ [/path/to/my/mozilla/mail]
+mhmboxquirks = tbird
+ It should be noted that later &RCL;
+ versions have improved automatic detection of
+ Thunderbird folders, so that this
+ should not be needed at all in most cases.