Task 7 refers to RFC number 2822.
The RFC doesn't seem to say anything out requiring a TLD for the domain part of an e-mail address. A host could be using a DNS server serving internal TLDs.
I don't understand what part of the RFC disallows these:
val@val
val@val.a.a.a.a
Could someone please point out where these are disallowed or clarify what is actually expected for Task 7? I'd rather not write a regex for this RFC if the address syntax in the RFC isn't actually what is expected.
Thanks!