Description of problem:

This is a follow-up for Bug 750210.

RFC 1025 states:

<snip>
 If the <local-part> contains dots or other special characters, its
representation in a master file will require the use of backslash
quoting to ensure that the domain name is properly encoded.  For
example, the mailbox Action.domains@ISI.EDU would be represented as
Action\.domains.ISI.EDU.
</snip>

This is not followed in ipa:

# ipa dnszone-mod idm.lab.bos.redhat.com --admin-email=foo.bar@example.com
  Zone name: idm.lab.bos.redhat.com
  Authoritative nameserver: vm-063.idm.lab.bos.redhat.com.
  Administrator e-mail address: foo.bar.example.com.
  SOA serial: 2011021101
  SOA refresh: 3600
  SOA retry: 900
  SOA expire: 1209600
  SOA minimum: 3600
  Active zone: TRUE
  Dynamic update: FALSE

Version-Release number of selected component (if applicable):
ipa-server-2.1.3-8.el6.x86_64

How reproducible:


Steps to Reproduce:
1. Run ipa dnszone-mod idm.lab.bos.redhat.com --admin-email=foo.bar@example.com
2. Check new admin email
3.

Actual results:
Is set to foo.bar.example.com

Expected results:
Should be set to  foo\.bar.example.com