Description of problem:
"  --zonemgr=ZONEMGR     DNS zone manager e-mail address. Defaults to root"

As part of negative testing, I provided an email id without "@" to --zonemgr
option and expected it to fail. I tried to send mail to just "root" using
commandline and checked the logs to find that the mails were directed to
"root@$HOSTNAME". So when we say "e-mail address" we should atleast check for
"@".

Version-Release number of selected component (if applicable):
ipa-server-2.1.2-2.el6.x86_64

How reproducible:
Always

Steps to Reproduce:
1. Install IPA Server Master with all default options, do not install with
--setup-dns
2. [root@bumblebee ~]# ipa-dns-install --zonemgr=123


Actual results: setup of DNS for the IPA Server is successful.


Expected results:
[root@bumblebee ~]# ipa-dns-install --zonemgr=123
Usage: ipa-dns-install [options]

ipa-dns-install: error: option --zonemgr: invalid email address 123


Additional info: