What is wrong with this regex for matching emails?

[Peter J. Holzer]

On 2017-12-20 08:21:02 +1100, Chris Angelico wrote:
> If there are no MX records for a domain, either the domain doesn't
> exist, or it doesn't receive mail.

This is not necessarily correct. An MTA has to fall back to A and AAAA
records if no MX record exists, so a domain can receive mail without an
MX record. This is rare, but I have seen it in the wild (although
usually not for email addresses for people but for services (e.g.
trouble ticket systems).

        hp

-- 
   _  | Peter J. Holzer    | we build much bigger, better disasters now
|_|_) |                    | because we have much more sophisticated
| |   | hjp at hjp.at         | management tools.
__/   | http://www.hjp.at/ | -- Ross Anderson <https://www.edge.org/>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 833 bytes
Desc: not available
URL: <http://mail.python.org/pipermail/python-list/attachments/20171221/241bf25c/attachment.sig>