Outlook: new and classic

Module 2: Setting up your mailbox · Reading time: 10 minutes

Learning objective: After this lesson, you can set up an IMAP mailbox in the new and classic Outlook for Windows and in Outlook for Mac, and you know what the difference means for where your mail and your password end up.

Key concepts: new Outlook, classic Outlook, Outlook for Mac, Outlook app on your phone, syncing with the Microsoft Cloud, IMAP, Exchange, .ost and .pst files, manual setup

Two programs with the same name

"Outlook" is now an umbrella term. On a Windows computer, you might come across two very different programs:

The old Windows apps Mail and Calendar have not been supported since late 2024; anyone who used them is automatically moved to the new Outlook. As a result, many people end up with the new Outlook without having chosen it.

What "via the Microsoft cloud" means

This is the most important difference, and few people know about it. Classic Outlook, Thunderbird and Apple Mail connect to your IMAP server themselves. Your password stays only on your own computer.

The new Outlook works differently. Microsoft calls it "syncing your account with the Microsoft Cloud": a Microsoft server logs in to your mail server on your behalf, retrieves your mail and keeps a copy in Microsoft's data centres. The new Outlook on your computer then talks to Microsoft, not to your own mail server. In exchange, Microsoft receives your email address, your password and a copy of your mail, calendar and contacts. Microsoft itself states that its own terms and privacy statement then also apply to that data. The same applies to the Outlook app on iPhone and Android and, unless you switch it off, to Outlook for Mac.

Consequences you'll notice in practice:

• Delay. New mail sometimes only appears after a while, because Microsoft has to fetch it first.
• Vague error messages. If Microsoft fails to log in, all you see is "something went wrong". You can't tell whether it's the password, the port or the certificate.
• Login attempts from an unfamiliar IP. Your mail server sees login attempts from Microsoft's servers, not from your own internet connection. After a few failed attempts, such a server can get blocked, and then things stop working for quite a while.
• Privacy and regulations. For some organisations (healthcare, government, legal) business mail must not end up with a third party without good reason. In that case, the new Outlook with an IMAP account is a problem for GDPR compliance.

If you don't want this, use classic Outlook (for as long as Microsoft keeps offering it), Thunderbird (lesson 2.5), or on a Mac, Apple Mail (lesson 2.3). In Outlook for Mac, you can turn off syncing with the Microsoft Cloud when adding an IMAP account.

Setting up classic Outlook

1. Click File and then Add Account.
2. Type your email address. Click Advanced Options and tick Let me set up my account manually. Click Connect.
3. Choose IMAP.
4. Incoming mail: server name, port 993, encryption method SSL/TLS.
5. Outgoing mail: server name, port 587 with STARTTLS (or 465 with SSL/TLS).
6. Click Next, enter the mailbox password, click Connect. If Outlook asks for a username, enter your full email address.

If you end up in an older Account Settings window, choose a new account of type IMAP and enter the same details. Under More Settings, tab Outgoing Server, turn on that the outgoing server requires authentication, with the same settings as the incoming server.

Setting up the new Outlook

1. Open Settings (gear icon) and then Accounts.
2. Choose Add Account, type your email address, click Continue.
3. Choose IMAP when Outlook asks what type of account it is.
4. Open the advanced settings (or "more options") so you can enter the servers yourself.
5. Incoming: server name, port 993, SSL/TLS. Outgoing: server name, port 587 STARTTLS or 465 SSL/TLS. For both, your full email address and the password.
6. Click Continue. Outlook asks for permission to sync the account with the Microsoft Cloud. Without that permission, adding the account will not work.

Pitfalls with Outlook

Outlook decides on its own that it's Exchange or Microsoft 365. Outlook first tries autodiscover (lesson 2.1). If it finds nothing or something incorrect, it sometimes assumes your address is a Microsoft account and keeps asking for a Microsoft password. An ordinary mailbox at a hosting company is not an Exchange account. Always choose IMAP (or POP3) manually.

Sent mail is stored locally. In older versions, or with an incorrect folder mapping, Outlook puts sent mail in a "Sent Items" folder on your computer instead of in the Sent folder on the server. Then you won't see that mail on your phone. How to fix this is covered in lesson 3.1.

The .ost and the .pst. Classic Outlook stores an IMAP account in an .ost file: a copy of what's on the server, which Outlook can rebuild itself. A POP3 account or an archive is stored in a .pst file: that's the only place where that mail exists. So make sure you back up a .pst file. A broken .ost can be deleted; Outlook will fetch everything again from the server.

Large mailboxes. Classic Outlook lets you set, for an IMAP account, how much mail is kept offline on your computer (for example, the last 12 months). If that period is short, older mail may seem to be missing, while it's actually still on the server. You'll then see a message saying there are more items on the server. Increase the period in the account settings if you also want to search old mail on your computer.

A new password. If you've changed the mailbox password, Outlook usually asks for the new one automatically. In classic Outlook, you change it via File, Account Settings; in the new one, via Settings, Accounts. Don't forget your other devices, or the server might block your IP address (lesson 1.4).

Outlook for Mac and on your phone

You set up Outlook for Mac via the Outlook menu, Settings, Accounts, the plus sign, New Account. Choose IMAP and enter the same details. Watch out for the tick box for syncing with the Microsoft Cloud.

The Outlook app on iPhone and Android always works via the Microsoft cloud. On a phone, the built-in mail app (Apple Mail, the Gmail app) is usually the simpler choice (lessons 2.3 and 2.4).

In practice: Outlook with a hosting mailbox

For a mailbox from WebOké, you enter in Outlook: IMAP, your domain name or the server name of your package, port 993 SSL/TLS, outgoing 587 STARTTLS or 465 SSL/TLS, your full email address and the mailbox password. With the new Outlook, the connection runs via Microsoft, so the mail server sees login attempts from Microsoft. With other providers it works in a similar way; only the server name differs.

Summary

• There are two Outlooks for Windows: the classic one (direct to your mail server) and the new one (via the Microsoft cloud).
• The new Outlook gives Microsoft your password and a copy of your mail. If you don't want that, use classic Outlook, Thunderbird or Apple Mail.
• Always choose IMAP manually; a hosting mailbox is not an Exchange account.
• An .ost is a copy of the server; a .pst is often the only place where mail is stored, so back it up.

Quiz

Exercise

Exercise O2.2: Setting up and checking Outlook. Do you use Outlook? Find out which version you have (classic, new, Mac or app) and set up your mailbox, or check the existing settings. Fill in the checklist: account type, incoming server and port, outgoing server and port, security, username for incoming and outgoing, outgoing authentication on, and whether the account runs via the Microsoft Cloud. Finally, answer: is that last point a problem for you or your organisation, and why? The program will then show the criteria.

Further reading

The steps in these articles apply to WebOké's control panels; with other providers it works in a similar way.

• DirectAdmin guide 8.2: Outlook for Windows (new and classic)
• DirectAdmin guide 8.3: Apple Mail and Outlook on the Mac
• Adding a mailbox to Outlook
• Microsoft Support, "Sync your account in Outlook to the Microsoft Cloud" (Microsoft's explanation of syncing via the cloud)