Roundcube doesn't use real name as identity

Hi there!
Up till now I could find everything I needed somewhere on the net, when I stumbled upon problems for my first steps with virtualmin/webmin/usermin. But I can’t for the love of god find where to set the following: When I send mails from my virtual server email accounts (which have usernames of the form username.domain) they show username.domain as ?real name? (the “from” column in Thunderbird) instead of the real name I entered when creating the account. Also I’d like to be able to change what is shown for this string even if it may not be a real name but rather the name of an organization or project. I guess I could use the real name string for this but well, it doesn’t work. On another note: If anyone knows where I could find some kind of postgrey-log so I could check if emails are only being greylisted rather than not getting them at all I’d really appreciate that.

Thanks for reading :).

EDIT: Well, 5 minutes after posting this I realized that roundcube is responsible for this “identity”. Why does roundcube use username.domain as email account identity even though I initialized the account with a real name?