How do you get maintenance notices to the people who actually need them?

Send notices directly to affected users instead of relying on departments to forward them. Distribution groups by application or department would make that easier. Even a targeted BCC list is a start if you don't have groups set up yet.

Agree with department leads on who keeps those lists current. For maintenance that affects a whole location or most employees, a broader group is reasonable. Not every small change needs an all-staff email.

Put the warning where people encounter the service, if the application supports it. A banner or in-app message can back up the email and catch someone who missed it.

Keep the message clear about the date, time, expected interruption, and which service is affected. Point users to the email for any extra details.

A predictable maintenance window can help. Pick a regular day and time if that works for the business, then send a reminder before each window. People still need separate notice for work outside the normal schedule, especially urgent patches.

There's a process problem here, not just a channel problem. If department leads are expected to pass notices along, make that responsibility explicit and check whether they can actually do it reliably. Otherwise, sending the same notice to a different department inbox probably won't change much.

Some people take the view that sending an email is enough and reading it is the user's responsibility. That's a clearer arrangement when the email goes to the user in the first place.

Use more than one place for major outages, but keep the noise under control. Depending on what staff already use, that could be a chat announcement, help desk or status page, digital signage, or a short item in a regular bulletin. A small application update probably doesn't need all of those.

If you use chat, consider an announcement-only channel so maintenance notices don't get buried under unrelated support requests.