use MIME::Lite;    
#...
push @rueckgabe, "Sende E-Mail an $empfaenger_mail, result=".$mime_msg->send;

Sende E-Mail an [EMAIL=gueltig@knoefler.com]gueltig@knoefler.com[/EMAIL], result:1

Apr 14 15:22:37 1234567 qmail-queue: dwlib[30712]: mail: all addreses are uncheckable - need to skip scanning (by deny mode)
Apr 14 15:22:37 1234567 qmail-queue: dwlib[30712]: scan: the message(drweb.tmp.4Vs5tz) sent by [EMAIL=anonymous@1234567.meinserver.net]anonymous@1234567.meinserver.net[/EMAIL] to [EMAIL=foo@bar.com]foo@bar.com[/EMAIL] should be passed without checks, because contains uncheckable addresses
Apr 14 15:22:37 1234567 qmail: 1145020957.466667 new msg 7243010
Apr 14 15:22:37 1234567 qmail: 1145020957.466810 info msg 7243010: bytes 1491 from <anonymous@1234567.meinserver.net> qp 30713 uid 10009
Apr 14 15:22:37 1234567 qmail: 1145020957.615793 starting delivery 1: msg 7243010 to local [EMAIL=56-sbar@bar.com]56-sbar@bar.com[/EMAIL]
Apr 14 15:22:37 1234567 qmail: 1145020957.615940 status: local 1/10 remote 0/20
Apr 14 15:22:37 1234567 qmail: 1145020957.620311 delivery 1: failure: This_address_no_longer_accepts_mail./
Apr 14 15:22:37 1234567 qmail: 1145020957.620592 status: local 0/10 remote 0/20
Apr 14 15:22:37 1234567 qmail-queue: dwlib[30716]: mail: all addreses are uncheckable - need to skip scanning (by deny mode)
Apr 14 15:22:37 1234567 qmail-queue: dwlib[30716]: scan: the message(drweb.tmp.z6DRF0) sent by  to [EMAIL=anonymous@1234567.meinserver.net]anonymous@1234567.meinserver.net[/EMAIL] should be passed without checks, because contains uncheckable addresses
Apr 14 15:22:37 1234567 qmail: 1145020957.841767 bounce msg 7243010 qp 30716
Apr 14 15:22:37 1234567 qmail: 1145020957.841811 end msg 7243010
Apr 14 15:22:37 1234567 qmail: 1145020957.861182 new msg 7243025
Apr 14 15:22:37 1234567 qmail: 1145020957.861303 info msg 7243025: bytes 2087 from <> qp 30717 uid 2522
Apr 14 15:22:37 1234567 qmail: 1145020957.989972 starting delivery 2: msg 7243025 to remote [EMAIL=anonymous@1234567.meinserver.net]anonymous@1234567.meinserver.net[/EMAIL]
Apr 14 15:22:37 1234567 qmail: 1145020957.990079 status: local 0/10 remote 1/20
Apr 14 15:22:37 1234567 qmail: 1145020957.994270 delivery 2: failure: Sorry._Although_I'm_listed_as_a_best-preference_MX_or_A_for_that_host,/it_isn't_in_my_control/locals_file,_so_I_don't_treat_it_as_local._(#5.4.6)/
Apr 14 15:22:37 1234567 qmail: 1145020957.994537 status: local 0/10 remote 0/20
Apr 14 15:22:38 1234567 qmail-queue: dwlib[30719]: mail: all addreses are uncheckable - need to skip scanning (by deny mode)
Apr 14 15:22:38 1234567 qmail-queue: dwlib[30719]: scan: the message(drweb.tmp.gSXfJu) sent by #@[] to [EMAIL=postmaster@1234567.meinserver.net]postmaster@1234567.meinserver.net[/EMAIL] should be passed without checks, because contains uncheckable addresses
Apr 14 15:22:38 1234567 qmail: 1145020958.198051 bounce msg 7243025 qp 30719
Apr 14 15:22:38 1234567 qmail: 1145020958.198097 end msg 7243025
Apr 14 15:22:38 1234567 qmail: 1145020958.198411 new msg 7243023
Apr 14 15:22:38 1234567 qmail: 1145020958.198544 info msg 7243023: bytes 2701 from <#@[]> qp 30720 uid 2522
Apr 14 15:22:38 1234567 qmail: 1145020958.330942 starting delivery 3: msg 7243023 to remote [EMAIL=postmaster@1234567.meinserver.net]postmaster@1234567.meinserver.net[/EMAIL]
Apr 14 15:22:38 1234567 qmail: 1145020958.331045 status: local 0/10 remote 1/20
Apr 14 15:22:38 1234567 qmail: 1145020958.347342 delivery 3: failure: Sorry._Although_I'm_listed_as_a_best-preference_MX_or_A_for_that_host,/it_isn't_in_my_control/locals_file,_so_I_don't_treat_it_as_local._(#5.4.6)/
Apr 14 15:22:38 1234567 qmail: 1145020958.347386 status: local 0/10 remote 0/20
Apr 14 15:22:38 1234567 qmail: 1145020958.347405 triple bounce: discarding bounce/7243023
Apr 14 15:22:38 1234567 qmail: 1145020958.347423 end msg 7243023