From Debian package 0.0.20080702-15
0013-Add-debian-apache-paths-and-apache_script_exec_domai.patch

Label /var/lib/squirrelmail/data(/.*)? as httpd_squirrelmail_t.

Index: policy/modules/contrib/apache.fc
===================================================================
--- policy/modules/contrib/apache.fc.orig
+++ policy/modules/contrib/apache.fc
@@ -79,6 +79,7 @@
 /var/lib/httpd(/.*)?			gen_context(system_u:object_r:httpd_var_lib_t,s0)
 /var/lib/php/session(/.*)?		gen_context(system_u:object_r:httpd_var_run_t,s0)
 /var/lib/squirrelmail/prefs(/.*)?	gen_context(system_u:object_r:httpd_squirrelmail_t,s0)
+/var/lib/squirrelmail/data(/.*)?	gen_context(system_u:object_r:httpd_squirrelmail_t,s0)
 
 /var/log/apache(2)?(/.*)?		gen_context(system_u:object_r:httpd_log_t,s0)
 /var/log/apache-ssl(2)?(/.*)?		gen_context(system_u:object_r:httpd_log_t,s0)