[Dovecot] Strange issue with doveadm user

Dear all,

I encounter a strange issue with the *doveadm user* command. (dovecot 2.1.16)

I try to retrieve information about a specific user but dovecot says it doesn't exist (whereas I just created it). The following command fails:

$ sudo -u vmail doveadm user pouet@domain.tld userdb lookup: user pouet@domain.tld doesn't exist

If I try a more global lookup, the user is properly found:

$ sudo -u vmail doveadm user *@domain.tld user1@domain.tld *pouet@domain.tld*

Sending a query for another user works well. For example :

$ sudo -u vmail doveadm user user1@domain.tld userdb: user1@domain.tld home : /var/vmail/domain.tld/user1 uid : 500 gid : 500 quota_rule: *:bytes=100M

I really don't understand what's happening... The only difference I see between the users is that user1 was created when I was using dovecot 1.2...

Thanks for your help.