Attribute regex and modification

[Jarosław Sajko <jaroslaw.sajko@horyzont.net>]

hello,

I've such entry in my config:

access to dn.subtree="ou=Accounts,o=Company,c=PL"
        attrs="mail" val.regex="^s.+"
        by dn.base="cn=user,ou=Accounts,o=Horyzont Technologie 
Internetowe,c=PL" write
        by anonymous auth

And there is fine when I try to search the subtree, there appears only 
objects with mail attribute starting with 's' letter. But if I try to 
modify (i'm simply adding letter at the end of email address) then it 
fails, I receive such message:

May 25 11:40:01 dnscache1 slapd[2662]: [ID 177021 local4.debug] conn=0 
op=6 MOD dn="uid=user, ou=Accounts,o=Company, c=PL"
May 25 11:40:01 dnscache1 slapd[2662]: [ID 324647 local4.debug] conn=0 
op=6 MOD attr=mail
May 25 11:40:01 dnscache1 slapd[2662]: [ID 217296 local4.debug] conn=0 
op=6 RESULT tag=103 err=50 text=

What is the problem. I need to restrict modification of an email address 
to such pattern. Thanks for any hints.

--
regards,
js