Finally ... our emails are being seen by Yahoo! not as junk anymore. Hurray!
However I notice that the Yahoo! receiving MTA adds in a X-YMailISG header.
It's very large ... 2**10 bits?
Now that I've invested too large a chunk of my waking life in crafting our email headers I'm curious to know what an X-YMailISG header is. Can anybody tell me? Does it pose any security / authenticity issues? There's very little intelligible from Google results.
Background:
After many days tweaking TXT records in our domain's DNS zone file for SPF and DKIM, I have at last succeeded in generating email from our Drupal site that Yahoo! no longer marks as
X-YahooFilteredBulk and the excellent service
[email protected] returns results that show the emails passing SPF, DKIM and Sender-ID checks and appearing to SpamAssassin as ham. Yahoo! even adds a Received-SPF: pass header.
Useful links:
http://www.goldfisch.at/knowwiki/howtos/dkim-filter
http://old.openspf.org/wizard.html
Strangely enough the SPF TXT record needed / allowed a blank key / name field in our registrar's DNS management panel whereas the DKIM record needed the {selector}._domainkey as the key /name of the DKIM strings.