Re: *** ADMIN: Attention Yahoo users, please use another email service

On 4/15/2014 7:38 PM, DrFranken wrote:

As I understand the problem you can lurk all day long but posting from a
yahoo account causes many issues including OTHERS getting blocked!

So if you can see your own posts then you are not on a yahoo or other
provider using DMARC Reject=Y policy.

If you want to see if your mail provider has a DMARC policy, run the following command (replacing example.com with your domain name):

HOST HOSTNAME('_dmarc.example.com') TYPE(*txt)

If you see something like this:
_dmarc.yahoo.com descriptive text "v=DMARC1\; p=reject\; sp=none\; pct=100\;rua=mailto:dmarc-yahoo-rua@xxxxxxxxxxxxx,mailto:dmarc_y_rua@xxxxxxxxx\;"

Look at the p= attribute ... if it shows 'reject' then your domain has specified that, if a message isn't DKIM & DomainKeys signed AND doesn't come from a specific mail server, it should be rejected out of hand.

If the p= attribute is 'quarantine' then messages that don't pass the tests should be marked as spam but let through.
If the p= attribute is 'none' then no specific action should be applied to messages that don't pass the test.

If you see something like this:
Host _dmarc.att.net not found: 3(NXDOMAIN)

That means the domain doesn't publish DMARC policies and you will be fine.

david