X-YahooFilteredBulk

[John_Su]

i have a forum which emails new members for confirmation codes, but i was testing it out and then i realized that the email is being sent to
yahoo bulk mail folders.

i went ahead and looked at all the headers and found.
X-YahooFilteredBulk

since i have a block of 8 IP's i went ahead and change my server so that the e-mail client on sendmail sends through a different IP address, and i verified it by sending some email to myself and checking the headers.

sure enough looks like my whole block is blocked and tagged as spam. i just got this server in march of this year and i have never used sendmail on it.

i went ahead and installed it so i could use the phpBB forum software, and this happens.

could anyone direct me to solution? is there a way to tell yahoo that i am a legit non-spammer?

much thanks

[linear]

[antispam.yahoo.com...]

The exact criteria they use to inject the header aren't well-documented, so it's not possible for us to suggest a specific fix.

is there a way to tell yahoo that i am a legit non-spammer?

You can look into implementing domainkeys:
[antispam.yahoo.com...]

It's not trivial, and it's not entirely clear that it accomplishes your stated goal. Setting up a sendmail milter is not something many people can accomplish on their own. Even if you get it right, not every provider has adopted domainkeys, you'd probably need SPF records too.
[openspf.org...]

[John_Su]

is this the same thing to prevent the msn junk mail folder also?

[linear]

SPF is, yes:
[postmaster.msn.com...]

SPF is a lot easier for an individual webmaster to achieve than domainkeys. All you need to do is get a couple special txt records added to the zone file for your domain. Most hosting providers are getting hip to this and will play nice.