Gmail is detecting certain Outlook emails as spam

Even though Google has been working on countering spam in Gmail from other domains for a while, multiple Outlook accounts have recently received spam errors after emailing a Gmail account.

Microsoft’s support page has outlined the problem under ‘unable to send to Gmail with country domains’ under recent Outlook issues.

According to Bleeping Computer, affected users come from countries with Outlook.com domains. Upon sending emails from Outlook to Gmail, certain Outlook users receive a follow-up email from Gmail’s server with an error:

Image credit: Microsoft

Gmail detects the email as suspicious based on the reputation of the domain being sent. Google links a ‘why has Gmail blocked my messages‘ in error, sending users to the Gmail Help page. The page asks users to review Gmail’s bulk sender guidelines, which are slowly coming to all Gmail accounts this year.

Despite Google stating that only “suspicious-looking” emails would be blocked on their Gmail Help page, the platform appears to be blocking non-spam emails.

Microsoft’s support page has not disclosed why certain Outlook domains receive the spam error. However, the site prompts users under ‘Workload’ to be unable to send to Gmail with country domains to add an Outlook.com alias to their account and send emails to Gmail using that same alias.

MobileSyrup tested sending an email from Outlook to Gmail and found no spam messages appearing upon Gmail receiving the email.

Google said Gmail would reject non-compliant traffic from other email domains starting in April. Outlook looks to be the first of many email domains to receive large amounts of spam errors when sending an email to Gmail accounts.

Source: Microsoft Via: Bleeping Computer