• by Ray Schultz , Columnist, April 3, 2024

Gmail’s program of blocking possible spam emails is working well — perhaps too well. 

Some Microsoft Outlook account users are having their emails blocked by Gmail, according to a report by Bleeping Computer. 

Gmail is advising these senders that the “message is likely suspicious due to the very low reputation of the sending domain,” the report says. But it is not clear that these emails are spam. 

Gmail has been stating for months that it will begin blocking unauthenticated emails from bulk senders in April, and it already is rejecting a percentage of noncompliant traffic. Yahoo Mail is enforcing an identical policy.

The number of blocked emails is small. 

What can be done by the few affected Microsoft accounts? 

In what seems to be an unnecessary swipe, Gmail advises Microsoft to study its new guidelines if it wants to improve deliverability to Gmail addresses. 

In the meantime, Microsoft says it is working on the issue. Pending resolution, it advises blocked senders to add an Outlook.com alias to their accounts and use it when emailing Gmail accounts, Bleeping Computer adds.

Microsoft reportedly confirmed the issue, but said it only affects users with Outlook.com country domains, the report says.

The tools that support authentication include DKIM (DomainKeys Identified Mail), SPF (sender policy framework) and the self-protective device DMARC (domain-based message authentication, reporting, and conformance).

None is a panacea by itself, but together they ensure that you are who you say you are. 

“When you don’t authenticate, anyone can send email as you,” said Seth Blank, chief technology officer, Valimail, in a recent Valimail webinar on the subject.