Spamcop mail changes

Spamcop is shutting down it’s email service. While anyone could report spam using Spamcop, the system also provided users email addresses behind the Spamcop filters. This shut down should have no major impact on senders. Email addresses in use will still be accepting email, but that mail will simply be forwarded to another address, instead of users being able to access it through POP or IMAP.
The one problem some senders may have is IF they are solely authenticating through SPF and they are publishing a p=reject DMARC statement. This may result in some of the mail being rejected at the forwarding mail server, like AOL, Yahoo and other services respecting DMARC policy statements.
User forwarded mail will be coming from 68.232.142.20 (esa1.spamcop.iphmx.com) and 68.232.142.151 (esa2.spamcop.iphmx.com). If you don’t want to apply DMARC policy to known forwarded mail, those are the IPs to special case.

DMARC and report size limits
September 2014: The Month in Email

Related Posts

AOL admits to security breach

According to Reuters AOL has admitted there was a breach of their network security that compromised 2% of their accounts. Users are being told to reset their passwords, and security questions.
AOL started investigating the attack after users started reporting an uptick in spam from aol.com addresses. This spam was using @aol.com addresses to send mail to addresses in that user’s address book.
According to the AOL mail team, they are still investigating the attack, but they do not believe financial information was compromised.  Their statement reads in part:

Read More

Who's publishing DMARC?

DMARC is a way for a domain owner to say “If you see this domain in a From: header and it’s not been sent straight from us, please don’t deliver the mail”. If a domain is only used for bulk and transactional mail, it can mitigate a subset of phishing attacks without causing too many problems for legitimate email.
In other cases, it can cause significant problems. Some of those problems impact discussion lists, but others cause problems for ESPs servicing small companies and individuals. ESP customers use their email addresses in the From: field; if they’re a small customer using the email address provided by their ISP, and that ISP publishes a DMARC record with p=reject, a large chunk of the mail they’re sending will bounce. When that happens recipients will stop getting their email, they’ll be removed from the mailing list due to bounces, and there’s some risk of blocks being raised against the sending IP address.
Because of that, it’s good to be able to see what consumer ISPs are doing with DMARC.
I’ve created a tool at dmarc.wordtothewise.com that regularly checks a list of large consumer ISPs and webmail providers and sees what DMARC records they’re publishing.
There are two main variants of DMARC records.
One is policy “reject” – meaning that mail that isn’t authenticated (or for which authentication has been broken in transit) will likely be rejected.
The other is policy “none” – meaning that the ISP publishing the record doesn’t want recipients to change their delivery decisions, but are asking for feedback about their mailstream, and how much of it fails authentication. That can mean that the ISP is evaluating whether or not to publish p=REJECT, or is in the process of deploying p=REJECT. Or it can just mean that they’re using DMARC to monitor where mail using their domain in the From: address is being sent from. There’s no way to tell which is the case unless they’ve made an announcement about their plans.
Hopefully this will be a useful tool to monitor DMARC deployment by consumer ISPs, and to help diagnose delivery problems that may be caused by DMARC.

Read More

DMARC and report size limits

I just saw an interesting observation on the dmarc-discuss mailing list. Apparently some of the larger providers who are implementing DMARC for inbound email may not be handling some of the grubbier corners of the spec perfectly. That’s not surprising at all – early adopters tend to deploy code that implements early versions of the draft specification – but I can see this particular issue tripping up people who are beginning to deploy DMARC for their outbound mail.
DMARC includes the feature of requesting feedback reports about authentication failures – you just include the email address you want them sent to as a mailto: URI in the rua= and ruf= fields:

Read More