Outlook.com DKIM signing done, now on to hotmail.com


A couple of months ago, I wrote a blog post that we were starting to roll out DKIM signing for our consumer email accounts sending from @outlook.com. These are for accounts that have been migrated from the old Hotmail/outlook.com infrastructure and onto our new Exchange Online infrastructure. Not all accounts have been migrated yet, so if you are an @outlook.com user and don't see DKIM signatures on your messages, it's probably because your account hasn't been migrated yet. DKIM signatures are also sent to external recipients, that is, outlook.com-to-outlook.com messages are not signed (we have other ways of authenticating for this type of direct traffic).

We finished outlook.com last week.

Next up is signing DKIM for migrated @hotmail.com users. Hopefully that goes a little faster.

Comments (2)

  1. Hi Terry,
    I have two live custom domains, which mailboxes have been grandfathered on to hotmail.com now outlook.com. Some of the mailboxes have been moved on to the latest outlook.com infrastructure (outlook.office365.com), so I decided to change the autodiscover CNAME record to point to the new infrastructure (autodiscover-s.outlook.com).
    While being in the DNS admin interface I have also checked the SPF records and that made me to check how DKIM/DMARC works on my migrated mailboxes and I ended up here 😉 on your blog with a great amount of interesting articles, thanks for it.
    Do you happen to know if taking care of the custom domains, I mean in regards to DKIM/DMARC is also planned?

  2. Peter says:

    I have the same request to add DKIM to my custom domain outlook.com account.

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