server (SLES11 SP4) is up 2 date. Curl is curl-7.19.7-1.42.1.
I break down my problem to one perl module: Net::SSLeay.
For clarification:
SMT::Utils uses NET::SMTP which uses IO::Socket::SSL with uses Net:SSLeay ant this module hangs in line 92:
IO::Socket::SSL is installed in version 2.022
Net:SSLeay is installed in version 1.64 but I tested also with 1.72 (or 1.74, in short the newest version downloaded via CPAN. Did a downgrade after all testings to version shipped with sles)
Found some posts in the internet related to "add_ssl_algorithms" but was not able to fix it...

Finally I commented the line 28 (see below) in Module NET::SMTP.pm and the rest of the SMT Modules seem to run without an error. Even mail were received with smt reports last night with this "workaround".
  # require IO::Socket::SSL;
Also found some posts to update openssl. After that some had solved their problem with Net:SSLeay. I don't want to compile openssl by myself, want to use the version of sles...
Maybe there is an rpm for sles11 with a newer version.... if someone want to research, feel free to do so

In the end SMT seems to work proper and thats what I needed.

Thanks for reporting back!