The 250ok Deliverability Guide

Email deliverability monitoring firm 250ok just released "the 250ok Deliverability Guide" and it provides a solid getting started point for the concepts behind deliverability, email authentication, sending reputation and best practices. It's a free download and you can find it here.

Apple Moves to "Quarantine" DMARC Policy

If you monitor these things, you might have noticed that Apple's consumer email domains (iCloud domains) --, and -- have moved to a "p=quarantine" DMARC policy. This means that if you have an email address in these domains, your ability to send outbound mail using an email service provider or other, non-Apple email platform to send mail, deliverability won't look so good. Mail may not be blocked outright (Apple didn't move to "p=reject") but moving to "p=quarantine" means it's much more likely that your mail could end up in the spam folder.

What to do if you have a, or email address: Continue to send mail, but only from your proper email client on your Mac or iOS device.

What not to do: Don't try to use an ESP to send mail with a from address in the, or domains. It'll fail necessary authentication checks and Apple's DMARC policy will drive most ISPs to put your mail in the spam folder.

I think this is a good move for Apple and a good move for people who hate phishing and spoofing. Making it harder for bad guys to misuse your domains is a good thing.

Reference: OMG Domains List (Oath, Microsoft, Google)

Once called MAGY, we shall now call them OMG, because OMG, they have a lot of domains. Or alternately, more accurately, we shall refer to them as the OMG Domains they are Oath, Microsoft, and Google. Oath is the name of the company that now owns the email systems that used to be separately managed by Yahoo, AOL and Verizon. Microsoft offers consumer webmail via their "OLC" (Outlook Consumer) domains, which I tend to call Hotmail or And let's not forget Google's very popular Gmail platform.

Need a list of all the consumer webmail domains for each of these providers? I've got you covered.

Dead email domain:

Did you know that UK Retailer Tesco offered email service? Me neither, but I'm not their target demographic. I assume they did or do offer internet service and that the email service perhaps went along with that.

Anyway, as of June 27, 2018, the email service at is no more. Users are advised that if they have set up email forwarding, it will continue to work until October 10, 2018. If users had not set up email forwarding before the shutdown on June 27, they are out of luck.

Tesco has published a FAQ that you can find here.

What should senders do? It sounds like there's a chance a few users are still receiving mail by way of having it forwarded to some other address. If you want to try to keep in touch with as many of those people as possible, it might be wise to target subscribers with a "please update your email address" campaign before October 10th. There is no way for senders to automatically know what the updated address for a subscriber will be; the subscriber will have to choose to tell you.

After October 10th, it's time to stop sending mail to, as that mail will not get through to any real people. And continuing to send to a dead domain can lead to you hitting spamtrap addresses, if they later repurpose the domain to become a spamtrap domain. Or if they let the domain lapse and somebody else picks it up.

H/T: Arnaud Clément-Bollée