Here's how I configured my roundcube's password plugin to keep things together ($roundcubefolder/plugins/password/config.php)

$config['password_algorithm']        = 'dovecot';

$config['password_algorithm_prefix'] = '{SHA512-CRYPT}';

$config['password_dovecotpw_method'] = 'SHA512-CRYPT';

$config['password_query']            = "UPDATE mail.users SET password=%P WHERE email=%u LIMIT 1";

I left other fields alone.

Yassine.

Thanks much better info than I was seeing in my googling.  Except I would not use %p:

// The SQL query used to change the password.
// The query can contain the following macros that will be expanded as follows:
//      %p is replaced with the plaintext new password
//      %c is replaced with the crypt version of the new password, MD5 if available
//         otherwise DES.
//      %D is replaced with the dovecotpw-crypted version of the new password
[...]

%D seems to be what I want...

the rcmail_config[] syntax you pasted in your mail indicates you're using a very old version of roundcube. Here's the relevant content of my version of the password plugin :

// The SQL query used to change the password.

// The query can contain the following macros that will be expanded as follows:

//      %p is replaced with the plaintext new password

//      %P is replaced with the crypted/hashed new password

//         according to configured password_method
[...}

// Deprecated macros:

//      %c is replaced with the crypt version of the new password, MD5 if available

//         otherwise DES. More hash function can be enabled using the password_crypt_hash

//         configuration parameter.

//      %D is replaced with the dovecotpw-crypted version of the new password
[...]

Notice the difference b/w %p and %P. Also notice that %D is marked as deprecated.

And in mysql, I believe the table is mailbox.

I got from: https://kaworu.ch/blog/2016/04/20/strong-crypt-scheme-with-dovecot-postfixadmin-and-roundcube/

Ah, it seems Aki and I have already visited this link before ^^'

Yassine.