Dell OpenManage Error GPG apt-get / the public key is not available: NO_PUBKEY E74433E25E3D7775

Error:

GPG error: http://linux.dell.com Release: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY E74433E25E3D7775

gpg --keyserver pgpkeys.mit.edu --recv-key E74433E25E3D7775
gpg -a --export E74433E25E3D7775 | apt-key add -