Emails fail to send resulting in a 554 error when using Microsoft Office365 SMTP serverIssue When sending emails from the instance using a Microsoft Office365 SMTP server, and using different email addresses in the From field, some From field settings work, while others fail, resulting in a send-failed state. The following error message displays: 554 error: 554 5.2.0 STOREDRV.Submission.Exception:SendAsDeniedException.MapiExceptionSendAsDenied; Failed to process message due to a permanent exception with message Cannot submit message. ReleaseApplies to any release.CauseThe Microsoft Office365 SMTP server is rejecting the set From address.ResolutionThis issue needs to be addressed by Microsoft. Contact Microsoft Support, show them the error, and ask how to configure the email server to accept multiple From addresses.