Exchange Online Mail Flow Rules Move to New EAC

Part of the Ongoing Transition from the Legacy EAC

The ongoing saga of the transition from the old Exchange admin center (EAC) to the super-duper modern edition continues. The latest move involved mail flow rules (aka transport rules), described in Message center notification MC449929 (25 October). Microsoft flags the change as a major update, but it really isn’t because it will affect the very small minority of people who work with mail flow rules.

Microsoft will begin to retire the mail flow rules section from the old EAC in November and it should disappear from all tenants by the end of 2022. Eventually, the old EAC will disappear entirely. I won’t shed any tears when this happens as I never liked the layout of the now-legacy EAC (Figure 1). It is very much an artifact of a Microsoft design language that features large expanses of white space.

Mail flow rules in the old EAC
Figure 1: Mail flow rules in the old EAC

Two years ago, I noted that, despite missing some useful functionality, the new EAC represents the future. Time flies when you’re having fun and the developers must be laughing merrily because the last two years has gone without a huge amount of progress. No doubt some will point out the difficulty of moving existing infrastructure to a new framework, but it’s not like Microsoft hasn’t done this before. It seems like some of the experience gained in transitioning other administrative portals hasn’t been used. For instance, refreshing access tokens is not done as smoothly in EAC as it is in the Microsoft 365 admin center.

An Enhanced UX

The Microsoft documentation assures us that the new UX (Figure 2) “has been enhanced and modernized. This updated experience is consistent with the new EAC design and will enable easier rule management.” It also points out that the new UX exposes more information about rules. You can see the effect by comparing how the legacy and new EAC display details of the same rule (to include a disclaimer to calendar meeting requests) in Figures 1 and 2.

Mail flow rules in the new EAC
Figure 2: Mail flow rules in the new EAC

With that point in mind, let’s consider the details.

Revised Workflows

Although Microsoft says that most workflows (how you create and work with rules) are unchanged, they highlight three major differences:

EAC disables newly-created rules. This is a smart move because it stops mail flow rules becoming active immediately on creation. It’s quite likely that some tweaking is necessary before making a rule active.

EAC features a new rule creation wizard to guide people through the configuration of mail flow rules. Mail flow rules can be quite complex and having a wizard sounds like a good idea, if the wizard wasn’t just plain broken. Take the example shown in Figure 3, which creates a simple disclaimer rule. Despite completing all the necessary steps, there’s no way to move to the next stage in the process. The wizard stays dumb and refuses to say what’s wrong, so there’s no obvious way to proceed and complete the rule. No doubt Microsoft will sort out this glitch and in the interim, there’s always the New-TransportRule cmdlet!

The new mail flow rules wizard has no way to move forward
Figure 3: The new mail flow rules wizard has no way to move forward

The “landing page” shows if rules stop processing when executed. Mail flow rules have a priority order which dictates the sequence of processing within the Exchange transport service. The stop processing rules setting exists to prevent Exchange running any remaining rules. For instance, if a rule rejects a message and issues a non-delivery notification, it’s appropriate for it to signal to Exchange Online that it should stop processing any remaining rules. Knowing what rules stop processing is obviously important, so Microsoft now highlights the setting in the list of rules (Figure 4)

Highlighting mail flow rules that stop processing
Figure 4: Highlighting mail flow rules that stop processing

What’s Missing for Mail Flow Rules

Moving the mail flow rules over to the new EAC is a good thing. It’s just disappointing that everything associated with the new EAC seems to happen so slowly (even if Microsoft isn’t moving some features, like bulk distribution list migration). Taking up so much time to perform what appears to be relatively straightforward tasks leaves less time to improve management of mail flow rules. Essentially, the same type of management of mail flow rules exists in Exchange Online that Exchange 2007 had 16 years ago. The interface is prettier, but the same functionality largely exists.

The processing of Mail flow rules can become very complex when an organization uses more than ten rules. It would be nice if Exchange Online delivered some way to visualize the path of a message through the set of defined rules to help administrators understand what happens as different rules run. Maybe Microsoft will get to something like this when they’ve completed the transition to the new EAC sometime in the next decade.


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2 Replies to “Exchange Online Mail Flow Rules Move to New EAC”

  1. The search functionality is also reduced. The new rules in EAC only searches the rule name, not the body. Making rule finding difficult if you have hundreds of rules.

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