Outlook.com Server Settings: IMAP, SMTP and POP3

Everything needed to connect Outlook.com to a mail client, in one place. These settings cover @outlook.com, @hotmail.com, @live.com and @msn.com addresses — one service, one set of values.

One caution before the table: on Outlook.com the settings are necessary but frequently not sufficient. How your client signs in matters as much as what you type into it, and that is covered directly below.

Outlook.com server settings

Your username is your full email address. Authentication is required on the outgoing server as well as the incoming one — if your client has a separate checkbox for that, tick it.

The incoming hostname looks like a business address, and people frequently assume they have the wrong settings because of it. They have not. Personal Outlook.com mailboxes run on the same infrastructure, and outlook.office365.com is correct for a consumer account.

Your password may not be the problem

This is the most common reason a correctly configured Outlook.com account still will not connect.

Microsoft retired basic authentication for Outlook.com — the arrangement where an application connects with just a username and password. Clients must now sign in through Microsoft itself, which issues a limited token and never handles your password directly. Anything that cannot do that is refused, regardless of how correct your settings are.

The signs are distinctive: the error 535 5.7.139, or a password prompt that reappears endlessly, or a setup that worked for years and stopped without you changing anything.

The test is simple. When you add the account, a compatible client opens a Microsoft sign-in page in a browser window. One that asks for your password in its own dialogue box is using the retired method.

Current versions of Outlook, Apple Mail, Thunderbird and the major phone apps all handle this correctly. If yours does not, update it or move to one that does. Our security guide covers this in more depth, including the confusing state of app passwords.

Work and school accounts are a different service

If your address was issued by an employer, school or university, you are probably on Microsoft 365 rather than consumer Outlook.com. The two are separate services, and using one's settings on the other produces authentication failures that look exactly like wrong credentials.

Microsoft 365 accounts use outlook.office365.com for incoming mail and smtp.office365.com for outgoing. Your administrator may also have restricted or disabled protocol access entirely, in which case no settings will work and the answer is to ask them rather than to keep trying.

If you are unsure which you have: an address ending @outlook.com, @hotmail.com, @live.com or @msn.com is consumer. Anything on a company or school domain is almost certainly not.

IMAP or POP3?

Choose IMAP unless you have a specific reason not to.

IMAP synchronises. Your mail stays on the server and every device sees the same mailbox — read something on your phone and it shows as read on your laptop, move it to a folder and it moves everywhere.

POP3 downloads and, by default, removes the server copy. That suits one narrow case — archiving mail permanently onto a single machine — and causes lasting confusion on any account used from more than one device, because mail collected by one device simply is not there for the others.

If you do use POP, check whether it needs enabling in Outlook.com's settings first, and set the "leave a copy on the server" option deliberately rather than accepting whatever your client defaults to.

Matching ports to encryption

Ports and encryption travel in pairs, and mixing them is the most common reason a correct-looking configuration refuses to connect. Port 993 expects SSL/TLS. Port 995 expects SSL/TLS. Port 587 expects STARTTLS for outgoing mail.

Take a port from one pairing and encryption from another, and the connection fails with an error that usually blames the network or your credentials — sending you looking in entirely the wrong place.

Never configure without encryption. An unencrypted connection exposes your credentials to anyone on the same network, and Microsoft refuses such connections anyway.

If it still will not connect

• Check how your client signs in — a Microsoft page in a browser, not a password box in the app.

• Check you are on the right service. Consumer settings on a business account, or the reverse, fail in a way that looks like a credentials problem.

• Check the port and encryption pairing against the table above.

• Check the username is your full address, including the domain.

• Try a mobile hotspot if sending times out — many networks block outbound mail ports, and a message that sends on mobile data confirms the network rather than your settings.

If the client connects but mail is not arriving at all, that is a different problem. Our troubleshooting guide covers storage, Focused Inbox, rules and blocked senders — which between them explain most missing mail, and one of which permanently bounces messages back to senders.