Hi clemenschicago,
try the following ldap queries to find the password last set time, userAccountControl (whether password expires), and the maximum password age:
# ldapsearch -h domain1.com -b dc=domain1,dc=com -D user@domain1.com -W '(sAMAccountName=user)' pwdLastSet userAccountCont
# ldapsearch -h domain1.com -b dc=domain1,dc=com -D user@domain1.com -W -s base maxPwdAge
Then query for the same properties, while authenticating as a user 'userB' from domain2.net :
# ldapsearch -h domain1.com -b dc=domain1,dc=com -D userB@domain2.net -W '(sAMAccountName=user)' pwdLastSet userAccountCont
# ldapsearch -h domain1.com -b dc=domain1,dc=com -D userB@domain2.net -W -s base maxPwdAge
Please post the results.