Right now, if you put "firstname.lastname@example.net" as the contact email in SOA record the Linode DNS Manager converts it into "firstname.lastname.example.net." . That's wrong, as it'd imply "firstname@lastname.example.net". I think proper output should be "firstname\.lastname.example.net.".
I'm quite sure that
RFC 1035 section 8 is still the authoritative specification for this.
Quote:
(...)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.