Well I use the same password and nick for everything so even if I messed it up it would still be ok
And btw i think I did it right :
as mail I tried with email@example.com
and with firstname.lastname@example.org
(web8_admin is the ISPconfig user for the site containing the webmail)
as mail server I tried mail.mydomain.com and the server ip address
as password I tried the SQL password, the ISP user password and the ISP admin password
I tried all the combinations and there isn't one that works...