cyrus umask

[Peter Hamtal]

Hello,

i have installed cyrus 2.2.12 on gentoo.

My problem is that the umask didn´t work like it should when moving
messages in thunderbird from one folder to another.


I use amavis on my system and want to set moved messages with following
permissions: 650
It worked when cyrus is delivering the mail through sieve to the
folders, but when i move a message in thunderbird i get following
permissions set in the folder for example "SPAM".
The permission is then 600 ?
I do not understand why ? What process of cyrus is moving messages when
they where moved with an MUA ?

My umask in imapd.conf is set to:
umask: 027
 
User and group of the imap spool Folders are:
cyrus:mail

group:
mail::12:mail,cyrus,postfix,amavis

Are there any security issues not to set the umask to 027 ?

Regards,
Peter