UseFriendlyFromLine seems to have no effect

Hello,

I made an update from 3.6.5 to 3.8.4. Everything works fine except mail: the “From:”-line is empty for mails outside our network. In our network Outlook displays the name, but not the email address.
Before the Update it worked. The settings are still the defaults:

UseFriendlyFromLine 1
FriendlyFromLineFormat “”%s via RT" <%s>"

Any ideas?

My environment:
Red Hat Enterprise Linux ES release 4 (Nahant Update 6)
Sendmail 8.13.1
Apache HTTPD 2.2.13
mod_perl 2.0.4
Perl 5.8.8.817

SendmailSetting:
SendmailArguments , “-oi -t -f mail@domain.com”)

Regards,
Tobias