Setting up Outlook on Windows — all versions

Microsoft Outlook on Windows is the mail client most of our business customers use. We’ll go through the most common versions — classic Outlook (2019/2021), Outlook 365 and the new Outlook in Windows 11.

Requirements

• Mailbox exists
• App password generated if 2FA is enabled (see app passwords)

Classic Outlook (2019, 2021, Microsoft 365)

Variant 1: Auto setup (try this first)

Outlook has an auto-setup feature that usually works with autodiscover. With correct DNS this often works right away:

1. Start Outlook → if no accounts are configured, the account setup dialog opens automatically.
2. Enter your email address → Connect.
3. Outlook asks for the account type → choose IMAP.
4. Server details are prefilled from DNS discovery — usually already correct.
5. Check the fields:

Field	Value
Incoming server	mail.xaweho.de, IMAP, port 993, SSL
Outgoing server	mail.xaweho.de, SMTP, port 587, STARTTLS
Username	full email address
Password	mailbox / app password

6. Connect. Outlook tests the connection.

Variant 2: Manual configuration

If auto setup fails:

1. File → Add account → Advanced options → Let me set up my account manually.
2. Choose POP or IMAP.
3. Fill in the fields as above.
4. Next → the connection is tested.

On “authentication failed”

Common causes:

• Wrong password: with 2FA enabled you need the app password, not the main password.
• SMTP authentication disabled: in the server settings, “outgoing server requires authentication” must be enabled.
• TLS version conflict: old Outlook versions can have problems with modern TLS. Fix: update Outlook to a current version.

Outlook encryption settings in detail

In File → Account settings → select account → Change → More settings → Advanced:

• Incoming server (IMAP): 993, SSL/TLS
• Outgoing server (SMTP): 587, STARTTLS

Both on SSL/TLS or STARTTLS — never on “None”.

Variant 3: Exporting / importing an Outlook profile

If you’ve already configured Outlook and want to set it up identically on a second machine — or as domain admin need to equip many employees with the same setup — use an Outlook profile.

Exporting the profile

1. File → Account settings → Data files.
2. “Data files” tab → note the .pst path.
3. Close Outlook.
4. Open the Registry Editor (regedit).
5. Export the key HKEY_CURRENT_USER\Software\Microsoft\Office\16.0\Outlook\Profiles\<Profilname> as a .reg file.

Importing the profile

On the target machine:

1. Outlook closed.
2. Double-click the .reg file → import into the registry.
3. Open Outlook → the profile is there, Outlook may ask for the password.

Careful: profiles are Outlook-version-specific. Importing an Outlook 2016 profile into Outlook 365 often works, but is not guaranteed. On a mismatch, better to set up fresh.

New Outlook (Windows 11)

Microsoft introduced a new, rewritten-from-scratch Outlook in Windows 11. It’s basically a web view where mails are routed through Microsoft servers. We don’t recommend it for third-party mail addresses like Mailcow — the new Outlook pipes your mail data through the Microsoft cloud, which is dicey privacy-wise.

If you want to use it anyway:

1. Open new Outlook → Add Account.
2. Mail address → Continue.
3. Microsoft asks: “Where are these messages stored?” → IMAP.
4. Server details as above.

It works with Mailcow, but Microsoft caches the data on its servers. If that raises privacy concerns: use classic Outlook or Thunderbird.

Windows Mail (the built-in app)

Windows 10/11 has a built-in Mail app, similar to the new Outlook. Setup:

1. Open the Mail app → Accounts → Add account → Advanced setup → Internet email.
2. Server details:

Field	Value
Email address	your full email address
Username	same
Password	mailbox / app password
Account name	your choice
Incoming server type	IMAP4
Incoming server	mail.xaweho.de:993
Outgoing server	mail.xaweho.de:587
SSL required	both enabled

Microsoft has deprecated the standard Mail app in Windows 11 — it’s being replaced by the “new Outlook”. For serious use, better classic Outlook or Thunderbird.

Outlook tips for daily use with Mailcow

Multiple accounts in parallel: Outlook supports any number of IMAP accounts at once. Private + business in one interface.

Search folder for the spam score: create a search folder in Outlook with the condition “header X-Spamd-Score contains 8” — you see right away which mails barely made it past the spam filter.

Rules: Outlook rules run locally — only while Outlook is open. For server-side filters use Sieve in webmail, then the rule runs at night too.

S/MIME attachment encryption: Outlook supports S/MIME for mail encryption. You have to get certificates from a CA — currently not included with xaweho, but Outlook handles it client-side.

Frequently asked questions

“Connection to server failed” Typo in the server name or port. Even more often: the workplace firewall blocks port 993 or 587. Test: open https://mail.xaweho.de:993 in a browser — the browser shows an SSL connection error, which is correct (it wasn’t HTTPS after all), but means: the connection works. If the browser times out immediately: the firewall is blocking.

Outlook asks for the password every time. Enable the “remember credentials” checkbox. In an Active Directory domain with group policies that can be blocked — ask IT.

Mails come in, but sending doesn’t work. Check the SMTP configuration — port 587, STARTTLS, outgoing server requires authentication enabled with the same login as IMAP.

Can I set up the account as an Exchange account? No. The “Microsoft 365 / Exchange” account type uses MAPI/EWS with autodiscover — that doesn’t work against Mailcow, and there’s no real Exchange push with us that way either. Take IMAP/SMTP for mail; calendar, contacts and tasks you pull from SOGo via CalDAV/CardDAV, in Outlook with the free CalDav Synchronizer plugin.

Outlook syncs huge mailboxes slowly. On the first sync, Outlook loads 1 year of mail by default. In the account settings under “cached mode”, reduce to “only 6 months” — performance improves considerably.

How secure are Outlook data files (.pst)? Not encrypted by default. If your laptop gets stolen, someone with physical access can open the .pst and read all mails. Solution: enable Windows BitLocker on the disk or protect the Outlook data file with a password (File → Account settings → Data files → Settings → Password).

What if Outlook crashes and the profile is broken? Outlook has a repair tool: Control Panel → Mail → Profiles → delete the broken profile → create a new one. Mails are on the server (IMAP), so they’re not lost.

What’s next

• Setting up Thunderbird
• App passwords for mail clients
• Server details reference