However this regular expression is incorrect, for several reasons:
domain name labels (including top-level domains) may also contain hyphens;
TLDs exist that are more than 4 characters long, e.g. .paris (and there are much longer TLDs on ICANN’s list).
On a closed test network where I was using domain names ending in .example, this causes an e-mail whose sender domain is sender.example to be labeled STATUS_THIRD by this plugin despite SPF, DKIM and DMARC passing, all at sender.example. Adjusting the {2,4} to {2,7} as a test yielded STATUS_PASS instead.
The following line uses a regular expression to attempt extracting the domain name of the From header:
https://github.com/pimlie/authres_status/blob/eba58333b1b8e3f0028796857719e77a4dfb767d/authres_status.php#L353
However this regular expression is incorrect, for several reasons:
.paris(and there are much longer TLDs on ICANN’s list).On a closed test network where I was using domain names ending in
.example, this causes an e-mail whose sender domain issender.exampleto be labeledSTATUS_THIRDby this plugin despite SPF, DKIM and DMARC passing, all atsender.example. Adjusting the{2,4}to{2,7}as a test yieldedSTATUS_PASSinstead.