Then you have a user sogo, but can you send it an email, it seems that qmail can't do that. I don't know if this is interesting , but here i can drop an email to the user sogo.
For you problem of /usr/sbin/sogo-ealarms-notify, maybe you should try to reinstall sogo-ealarms-notify, or reinstall all packages of sogo
For the record, smeserver-sogo doesn't provide binary, just an integration of sogo.