sending task logs per mail doesn't work

.09 13:09:52.448 scheduler   15  7184.514  1296.922MB .JavaMail Send smtp=smtp.sos to="oh@sos-berlin.com" subject="ERROR SCHEDULER-280 Process terminated with exit code 1 (0x1)"
.09 13:09:52.457 scheduler   16  7184.514  1296.922MB .[xc.insert 1, "javax.mail.MessagingException"]
.09 13:09:52.457 scheduler    0  7184.514  1296.922MB .[xc.insert 2, "IOException while sending message
.09 13:09:52.457 scheduler    0  7184.514  1296.922MB .no object DCH for MIME type multipart/mixed; 
.09 13:09:52.457 scheduler    0  7184.514  1296.922MB .	boundary="----=_Part_2_1689424703.1352462992448""]
.09 13:09:52.457 scheduler    0  7184.514  1296.922MB .[xc.insert 3, "send"]
.09 13:09:52.457 scheduler    0  7184.514  1296.922MB .email send: Z-JAVA-105  Java exception javax.mail.MessagingException("IOException while sending message
.09 13:09:52.457 scheduler    0  7184.514  1296.922MB .no object DCH for MIME type multipart/mixed; 
.09 13:09:52.457 scheduler    0  7184.514  1296.922MB .	boundary="----=_Part_2_1689424703.1352462992448""), method=send []
.09 13:09:52.457 scheduler    0  7184.514  1296.922MB .[xc.insert 1, "javax.activation.UnsupportedDataTypeException"]
.09 13:09:52.457 scheduler    0  7184.514  1296.922MB .[xc.insert 2, "no object DCH for MIME type multipart/mixed; 
.09 13:09:52.457 scheduler    0  7184.514  1296.922MB .	boundary="----=_Part_2_1689424703.1352462992448""]
.09 13:09:52.457 scheduler    0  7184.514  1296.922MB .[xc.insert 3, "get"]
.09 13:09:52.457 scheduler    0  7184.514  1296.922MB .[xc.insert 4, "rfc822_text"]
.09 13:09:52.457 scheduler    0  7184.514  1296.922MB .[ERROR Z-JAVA-105  Java exception javax.activation.UnsupportedDataTypeException("no object DCH for MIME type multipart/mixed; 
.09 13:09:52.457 scheduler    0  7184.514  1296.922MB .	boundary="----=_Part_2_1689424703.1352462992448""), method=get [rfc822_text]]
.09 13:09:52.457 scheduler    0  7184.514  1296.922MB .{scheduler} sos::scheduler::Scheduler_event::send_mail:
.09 13:09:52.457 scheduler    0  7184.514  1296.922MB .{scheduler} [WARN]   SCHEDULER-302  Error sending e-mail: Z-JAVA-105  Java exception javax.activation.UnsupportedDataTypeException("no object DCH for MIME type multipart/mixed;  
.09 13:09:52.457 scheduler    0  7184.514  1296.922MB .{scheduler} [WARN]   	boundary="----=_Part_2_1689424703.1352462992448""), method=get [rfc822_text]
.09 13:09:52.458 scheduler    0  7184.514  1296.922MB .{scheduler} [WARN]   (Task test/jobExit1:1749586) SCHEDULER-320  Could not send mail