[dns-operations] email address in SOA

Daniel Kalchev daniel at digsys.bg
Thu Dec 6 08:57:41 UTC 2012

On 06.12.12 06:29, Phil Pennock wrote:
> Gmail offers what was, at the time they introduced it, an _unusual_ 
> canonicalisation, which may have become more widespread now. It makes 
> a lot of sense. Gmail says that, for mail to one of their domains, 
> dots are not significant and canonicalise away. They're not wildcards, 
> they're just noise that's skipped. So phil.pennock and philpennock are 
> the same LHS. The dots from account sign-up are just remembered for 
> presenting as the normal form of the address.

Just for the record, Gmail (Google) hardly invented this notation. Gmail 
launched in like... 2004? About 15 years earlier (my memory) we had 
email systems employing it. Out of practical considerations: the UNIX  
login name field cannot contain dots so any account would be created 
without the dots, even if the requested e-mali address was supposed to 
have dots. Dots in LHS were handled via sendmail aliasing. I am talking 
about atomated e-mail provisioning systems, not handcrafting sendmail.cf.

As a side effect, when sending to that sendmail instance, both 
user.name at some.domain and username at some.domain would work (as long as 
username is under 16 characters long).

I believe this was widespread enough before Google ever existed and will 
likely be widespread long after they are history.


More information about the dns-operations mailing list