Having problems with mail delivery can be a very frustrating experience whether you’re the affected end user or the administrator responsible for ensuring that your end users are able to send and receive mail without issue. Unfortunately, issues with mail flow are not uncommon and will likely occur at some point in time whether your users’ mailboxes are hosted in Office 365, on-premise, or a combination of both.
In an effort to help you resolve these issues we have released the Mail Flow Guided Walkthrough (GWT) for troubleshooting problems sending and receiving mail or when mail is delayed in the following scenarios:
- The sender’s mailbox is hosted on Office 365 and the recipient’s mailbox is outside your organization.
- The sender’s mailbox is outside your organization and the recipient’s mailbox is hosted in Office 365.
- The sender’s and recipient’s mailboxes are both located in Office 365.
- The sender’s mailbox is hosted in Office 365 and the recipient’s mailbox is located on an on-premise Exchange server and both users are in the same organization.
- The sender’s mailbox is hosted on an on-premise Exchange server and the recipient’s mailbox is hosted in Office 365 and both users are in the same organization.
The goal of this walkthrough is to assist you in resolving these issues in a timely manner by focusing on the scoping and steps used to isolate and resolve problems.
I’d like to thank everyone who contributed to the development of this troubleshooter with special recognition going to the following folks: Tom Kern, Nitin Shukla, Sainath Vijayaraghavan, Jim Martin, Bruce Wilson, Stephen Gilbert, Scott Landry, Charlotte Raymundo, Mary Browning, Star Li, Chen Jiang, Victor Zhang.