* nixmagic.com / Posts / 2024-09-25 /
[Q&A] Why do emails from the McDonald's event not arrive?
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Hey everyone! Recently I've been told that there's an ongoing event in North America, where you can buy certain things from McDonald's and receive rewards in Genshin Impact. Apparently the rewards are sent by McDonald's via email, and people are not receiving those emails. Some receive them right away, others have to wait a long time.

So let's talk about that. As a postmaster, there are 2 things here that are relevant -- reputation and deliverability. Similar in nature, but distinct enough to each receive their own description. Let's start with reputation.

Reputation is the broadest stroke in which the wheat is separated from the chaff when it comes to email. It concerns your sending server(s)' IP address(es), as well as their domain name(s). Each can be singular or plural, for mine they're both plural. If you send a lot of spam (especially to spam traps), you'll find your domain(s) and/or IP address(es) on blacklists. Once I had my mail servers listed on SORBS' blacklist, and they reported to my hosting provider. The servers were temporarily disconnected from the internet as a result, until I resolved the issue with my hosting provider's customer support. Regardless of reports, being on a blacklist tanks your reputation pretty much immediately. So you'll want to delist yourself from those ASAP if you are legitimate. I think we can reasonably assume for McDonald's to be legitimate, and to not find themselves on blacklists. And according to MX Toolbox, that is indeed the case. Sometimes even mass mailing for newsletters or promotions can be erroneously considered spam though, and it is up to the receiving mail servers to determine what to do with those emails. Which brings me to deliverability.

Deliverability is the measure of how likely it is for a sender's emails to be delivered into a receiving mailbox, particularly inbox. Here we have to talk about the two biggest email providers in the world, Microsoft and Google. Together, they hold pretty much a duopoly over the email market. Sure, there's competitors like iCloud, Yandex and even the odd Yahoo account. And then there's small operators like myself. But that's only a very small fraction of the market, it's Microsoft and Google that run the show. Google is overall quite welcoming towards third-party providers, and will happily assume legitimacy if they have either good records on you, or have yet to make any (i.e. you're new). Microsoft on the other hand... Their filters assume illegitimacy unless proven otherwise, and will outright refuse delivery (formally called bouncing, like that guy at the night club) if they think you're trying to send spam. It's a very heavy-handed system, which is why many third-party providers will tell their users that they cannot deliver to Microsoft. Maybe that's what's happening here too.

As a user, there's not much you can do. This is what keeps postmasters up at night, and is our responsibility.. all day, every day. Do yourself a favour and never run a mail server yourself, keep your sanity. What you can do is to use Gmail if you're currently using a Microsoft account, deliverability is generally better there. Other than that though.. all you can do is wait. And I hope you learned something.

Published to: HoYoLAB