Outlook out of office works internally, but clients get no reply
Coworkers get your vacation notice right away, but a new client who emails you hears nothing back. External replies are on, so why is that client left out?
- Check external replies separately from your internal message. If first-time customers need your vacation notice, a contacts-only audience may exclude exactly the people you want to reach.
- Exchange normally replies once to each sender while out of office is enabled. A second message from an address that already received the notice is a poor test of whether replies still work.
- If a new, eligible sender receives nothing during the scheduled period, establish whether the original email reached your mailbox. Give your administrator the addresses and timestamp to investigate forwarding, delivery, and external-reply policies.
A vacation notice has a practical job: tell someone why they will have to wait and where an urgent request should go. An internal test proves only part of that arrangement. A colleague may receive your message while a prospective customer waits without knowing that you are away.
For a work Microsoft 365 mailbox hosted in Exchange Online, enabling external replies can still leave a new customer outside the selected audience. A sender who already received the notice may get no further reply even when the feature works. If neither condition explains the missing message, the next checks are incoming delivery and the company's external-reply policy. Other account types in Outlook do not necessarily offer this Exchange feature.
Make sure the notice belongs to the mailbox customers use
If Outlook contains both your personal and work accounts, identify the mailbox that received the customer's email before editing anything. Compare the destination address with the account whose automatic replies you are changing. Otherwise, a perfectly saved message can belong to the wrong account.
Microsoft's setup guide gives these routes: View → View settings → Accounts → Automatic Replies in new Outlook, Settings → Account → Automatic replies on the web, and File → Automatic Replies in classic Outlook for Windows. Turn automatic replies on, enable replies outside your organization, check the external message and dates, then save. In classic Outlook, review the Outside My Organization tab.
The dates in your prose do not control the schedule. A notice saying you leave on Monday can coexist with a Tuesday start time. Likewise, a test sent before the scheduled start does not establish that anything is broken. Exchange's scheduled state uses the configured start and end times. Read those beside the dates in your message.
If classic Outlook has no Automatic Replies button, check the account type. Microsoft's alternative for an account without this feature is a reply template and rule that requires Outlook to stay running. Built-in Exchange out of office runs on the server, so it does not require the desktop application to remain open. For an account hosted by another provider, such as Gmail, investigate that provider's vacation responder.
Should someone contacting you for the first time receive the notice?
The contacts-only option refers to the mailbox's contact list. Having exchanged email with a person is not enough reason to assume their address is saved there. Cornell's Outlook operating guide distinguishes replies to everyone outside the organization from replies to people in your personal contacts.
Consider an illustrative sales inquiry. Customer A regularly places orders and is a saved contact; customer B is requesting a quotation for the first time. With external replies restricted to contacts, A can receive your notice while B is excluded. From B's perspective, there is no indication of whether you are away or whether the inquiry needs to go elsewhere.
If only established contacts should receive the message, retain the restriction and check that the necessary addresses are saved. If new inquiries also need an alternative contact, an unrestricted external audience better matches that purpose. It does not identify “new customers” specifically. Write the external message for someone who may know nothing about your team.
An internal instruction such as “use the usual arrangement” will not help that person. An external message could instead say:
Thank you for your email. I will return on [date] and review inquiries then. For order or delivery questions that need a response before that date, please email [colleague or team address] and include your order number.
The message tells customers when to expect attention and whom to contact; it does not confirm that their order has been processed. Replace the placeholders and agree on coverage with the colleague named in the message. Receiving a notice is useful only if the recipient can act on it.
A second email from the same address can mislead you
You send a test from a personal account and receive the notice. A second test gets nothing. Exchange normally sends one out-of-office reply to each sender, even when that person sends several messages. The feature is not a receipt for every incoming email.
Use an external address that has not received the current notice, and record whether it is a saved contact. The example below compares a colleague and customers A and B. Assume a first message during the active period, successful delivery of the original email, and no separate policy blocking replies.
| Test sender | External contacts only | All external senders |
|---|---|---|
| Colleague in the same organization | Internal message | Internal message |
| Customer A, a saved contact | Eligible for the external message | Eligible for the external message |
| Customer B, not a saved contact | Excluded from the external audience | Eligible for the external message |
An internal success says nothing about which external column applies. If A receives a reply and B does not, check the contacts restriction. If both are eligible but neither receives anything, investigate beyond audience selection, after ruling out an earlier reply to either address.
A useful test note can be short: “External address B; not in contacts; first test today; 10:15; original received; no reply found.” Give each test a recognizable subject so you can match the incoming email to the observation. Repeating messages while changing several settings makes the results harder to interpret.
Disabling and re-enabling out of office resets its reply history. If the same address receives another notice after that reset, it does not establish that the original configuration was faulty: the sender became eligible for another reply. Test with a fresh address first, then record any setting you need to change.
Find the incoming email before diagnosing the missing reply
Look for the original test message in the work mailbox. If it never arrived, rewriting the vacation notice does not resolve the incoming delivery problem. If it arrived and a reply was generated, the investigation moves to the return journey.
Check Junk as well as the inbox. Microsoft's troubleshooting guide says an incoming message classified as spam and sent to Junk does not generate an out-of-office reply. At the other end, ask the tester to search for the notice outside their inbox too. These are different checks: whether your mailbox created a reply, and whether the tester can find it.
Forwarding deserves a precise question. Does the original email still get delivered to your mailbox? Microsoft's specific forwarding-related failure article describes forwarding without simultaneous delivery to the original mailbox, or a transport rule redirecting the message away. Without delivery there, the incoming email does not trigger that mailbox's notice.
This does not mean every forwarding arrangement is incompatible with out of office. If a colleague must receive inquiries during your absence, ask the administrator whether delivery to your mailbox can be retained alongside forwarding. Turning off a necessary handoff simply to obtain a vacation reply would leave the underlying work uncovered.
Report the address and time, not just “automatic replies are broken”
Once you have checked the audience, schedule, first-message status, and original delivery, a remaining failure may require an administrator. Exchange Online's remote-domain settings can override an individual's automatic-reply choices. Selecting external replies in Outlook does not override company policy.
Explain whether the failure affects one company's addresses or several unrelated domains. A configuration for a specific external domain takes precedence over conflicting default settings. That distinction helps determine what to inspect; it is not a reason to remove restrictions for every external destination.
Fill in the addresses and timestamp from your test in a request such as this:
The notice for [work mailbox] did not reach [external sender]. Their first test was sent at [date, time, time zone], and I found the original in my inbox. Replies are enabled for all external senders during that period. Please trace the incoming message and outgoing notice, and check the relevant external-domain policy and forwarding configuration.
Message trace lets an authorized administrator inspect receipt, rejection, deferral, and delivery using addresses and a time range. The reply travels in the opposite direction to the test email: its destination is the original sender. Supplying both addresses makes that investigation more specific.
After a correction, repeat the condition that failed. For a missed first-time inquiry, use an external sender outside your contacts who has not already received the notice. For a domain-specific problem, arrange a suitable test from that domain. Read the returned message for the correct return date and working alternative contact. That checks the arrangement the customer will actually rely on while you are away.