Quick tip for those putting alternate user names and passwords.  When you export your bindings file, BizTalk 2006 replaces the password for the user credentials with a VT_NULL inside the <TransportTypeData> element:

&lt;Password vt="1" /&gt;

Be careful, that vt="1" mean NULL, or in other words - no password.  So when you do this:

You might as well do nothing.  When the file receive adapter imports these bindings, it will not set a password.  However, the send adapter doe snot seem to care and will set the password fine.  Regardless, the proper form is to specify VT_BSTR attribute in the Password element:

&lt;Password vt="8"&gt;mysecret&lt;/Password&gt;

You can find this documented in the Biztalk binding file documentation:

Configuration Property Variable Types

File Adapter Configuration Properties