Why can't I find a colleague in the Outlook address book?
The short answer: if the person has only just been set up, desktop Outlook probably hasn't caught up yet. It uses a downloaded copy of the address book that usually only refreshes about once a day, so a new starter can take up to a day or so to appear. In the meantime, you can simply type their full email address and the message will still arrive.
How the Outlook address book works
When you search for a colleague in Outlook, you're searching the Global Address List (often called the GAL). It's the company-wide list of everyone in your Microsoft 365 account: staff, shared mailboxes, distribution lists and meeting rooms.
Desktop Outlook doesn't usually search the live list. To save time and work offline, it downloads a copy called the Offline Address Book. Microsoft regenerates that copy roughly once a day, and Outlook then downloads it on its own schedule. So there's a delay built in at both ends.
That's why the most common reason for a missing colleague is simply that they're new.
Check whether they're really missing
Before assuming something is broken, try these quick checks:
- Look in Outlook on the web. Go to outlook.office.com, start a new email and search for the person. Outlook on the web searches the live directory, so new people usually show up there within minutes or a few hours.
- Type their full email address. If you know it, type the whole thing into the To box. Outlook will send it even if the address book doesn't know them yet.
- Check the spelling. Search by first name, then by surname. A display name like "Sam (Accounts) Patel" can trip up a search.
- Ask when they were set up. If their account was created today, the honest answer is usually "wait until tomorrow".
If they appear in Outlook on the web but not in desktop Outlook, it's almost certainly the offline address book catching up.
Make desktop Outlook catch up sooner
You can ask Outlook to download the latest copy. On Windows, in classic Outlook, this is usually under Send / Receive > Send/Receive Groups > Download Address Book. Make sure the option to download changes since the last time is ticked, then click OK.
Bear in mind this only fetches the most recent copy Microsoft has made. If your colleague was added after that copy was created, they still won't appear until the next one. Patience is sometimes the only fix, annoyingly.
The new Outlook for Windows works much more like Outlook on the web, so it tends to show new people sooner.
Other reasons someone might be missing
If it's been a couple of days and they still don't appear anywhere, one of these is likely:
- They're hidden from the address list. An admin can tick a setting, usually called Hide from global address list, on any mailbox. It's often used for leavers, test accounts or shared mailboxes, and sometimes switched on by mistake.
- They're not actually a user in your Microsoft 365. Guests, freelancers and people at other companies aren't in your Global Address List. If you've added them as a contact in your own Outlook, they'll be in your personal Contacts instead.
- Their account wasn't fully set up. A user without a licence that includes email won't have a mailbox, so there's nothing to show. Our guide on how to add a user in Microsoft 365 covers the steps.
- Their name was changed. If someone has changed their name, search for both the old and new versions until the address book refreshes.
When to get help
If a colleague has been set up for more than a couple of days, appears in Outlook on the web, but still won't show in desktop Outlook after downloading the address book, something may be stuck on that computer. Your IT person can check the mailbox settings and, if needed, reset Outlook's offline address book files.
Common questions
Will my email reach them if they're not in the address book?
Yes. The address book is just a directory for finding people. If you type their full, correct email address, the message is delivered as normal.
Why does my colleague appear on my phone but not my laptop?
Phone apps and Outlook on the web usually search the live directory. Desktop Outlook on your laptop uses the downloaded offline copy, which updates less often.
Can I make the address book update instantly?
Not really. You can trigger a download in desktop Outlook, but you only get the latest copy Microsoft has prepared, and that's built roughly once a day. Using Outlook on the web or typing the full address are the quickest workarounds.
Why can I see people who left months ago?
Leavers stay in the address book until their account is deleted or hidden. It's worth tidying up, both for neatness and so nobody emails a mailbox that no one reads. Our free Microsoft 365 audit flags old accounts like these.
Want us to check yours?
Our free Microsoft 365 audit looks at your licences, security, email and backups, and tells you in plain English what to fix first. No card, no obligation.