Gmail is blocking Microsoft Outlook emails after Google recently implemented new mandatory bulk sender authentication requirements for Gmail. Microsoft has already acknowledged the issue and is working on a fix, though it has already provided a temporary workaround.
Gmail might flag some Microsoft Outlook emails as spam — You'll temporarily need an 'alias' to circumvent this issue : Read more
Gmail might flag some Microsoft Outlook emails as spam — You'll temporarily need an 'alias' to circumvent this issue : Read more