note 105657 deleted from function.filter-var by danbrown
| From: | danbrown@php.net | Date: | Tue, 06 Sep 2011 15:35:48 +0000 |
| Subject: | note 105657 deleted from function.filter-var by danbrown | ||
| References: | 1 | Groups: | php.notes |
| Request: | Send a blank email to php-notes+get-182979@lists.php.net to get a copy of this message | ||
Note Submitter: michael at squiloople dot com
----
sampathperera at hotmail dot com:
That is a (syntactically) valid address. There is nothing that prevents a TLD from having MX RRs.
filter_var() doesn't check to see if the domain name _exists_, only that is is of the right
_form_.
From RFC 5321:
2.3.5. Domain Names
A domain name (or often just a "domain") consists of one or more components, separated
by dots if more than one appears. In the case of a top-level domain used by itself in an email
address, a single string is used without any dots.
...
Only resolvable, fully-qualified domain names (FQDNs) are permitted when domain names are used in
SMTP. In other words, names that can be resolved to MX RRs or address (i.e., A or AAAA) RRs (as
discussed in Section 5) are permitted, as are CNAME RRs whose targets can be resolved, in turn, to
MX or address RRs.
------------
Run this:
print_r(checkdnsrr('ua', 'MX'));
Whoever controls that domain can have an email address ending in @ua.
In fact, I believe au@ua is an in-use address.