A phishing campaign has been discovered that pretends to be a non-delivery notifications from Office 365 that leads you to a page attempting to steal your login credentials. This new campaign was discovered by ISC Handler Xavier Mertens and states that “Microsoft found Several Undelivered Messages””. It then prompts you to click on the “”Send Again”” link in order to try sending the emails again. If a recipient clicks on the Send Again link
Source: security