Bob Young@fifonetworks@infosec.exchange
@Edent@mastodon.social
Your question sent me on a quest through RFC 5321, and I still don't know the answer. I'm guessing that more than one dot in a row isn't valid, but I've been wrong before.
Bob Young@fifonetworks@infosec.exchange
@Edent@mastodon.social
The 64 octet limit is legit, though.
RFC 5321
"The local-part of a mailbox MUST BE treated as case sensitive. Therefore, SMTP implementations MUST take care to preserve the case of mailbox local-parts. In particular, for some hosts, the user "smith" is different from the user "Smith". However, exploiting thecase sensitivity of mailbox local-parts impedes interoperability and is discouraged."
"Local-part = Dot-string / Quoted-string; MAY be case-sensitive"
"While the above definition for Local-part is relatively permissive, for maximum interoperability, a host that expects to receive mail SHOULD avoid defining mailboxes where the Local-part requires (or uses) the Quoted-string form or where the Local-part is case-sensitive."
"4.5.3.1.1.
Local-part The maximum total length of a user name or other local-part is 64 octets."
