How to find the SMTP server for Outlook?

For personal Outlook.com / Hotmail / Live accounts: SMTP server is smtp-mail.outlook.com on port 587 with STARTTLS. For business Microsoft 365 / Office 365 accounts: SMTP server is smtp.office365.com on port 587 with STARTTLS. The 'Outlook' name covers both products, but they have different SMTP servers — use the one matching your account.

How to find SMTP in Outlook desktop app?

Open Outlook → File → Account Settings → Account Settings → select your account → Change → More Settings → Outgoing Server tab. The SMTP server is shown there. For Microsoft 365 accounts auto-configured via Exchange, SMTP isn't directly exposed because Outlook uses native protocols, not SMTP.

Where to find the SMTP server name?

Check your email provider's documentation under 'SMTP settings' or 'Server settings.' Most providers list this prominently. For business hosted email (Microsoft 365, Google Workspace), check your admin dashboard. For ESPs (SendGrid, Mailgun), check API/SMTP settings in your account dashboard.

How to find out your mail server name?

Three ways: 1) Check your email provider's website under 'Server settings' or 'SMTP settings.' 2) For business email, ask your IT admin. 3) For automated discovery, query DNS for MX records (returns incoming server) — note that MX is for INBOUND mail, not necessarily the same as SMTP for outbound.

What's the SMTP address vs SMTP server name?

Same thing. SMTP address, SMTP server name, SMTP server URL, SMTP hostname all refer to the DNS hostname your email client connects to for outgoing mail. Examples: smtp.gmail.com, smtp-mail.outlook.com, smtp.sendgrid.net. They resolve to one or more IP addresses but you connect via the hostname.

Find Your SMTP Server Name: Every Major Provider Reference

Quick Reference: SMTP Server Names

Provider	SMTP Server	Port	Encryption
Gmail / Workspace	smtp.gmail.com	587	STARTTLS
Gmail Workspace Relay	smtp-relay.gmail.com	587	STARTTLS
Outlook.com / Hotmail / Live	smtp-mail.outlook.com	587	STARTTLS
Office 365 / Microsoft 365	smtp.office365.com	587	STARTTLS
Yahoo Mail	smtp.mail.yahoo.com	587	STARTTLS
iCloud Mail	smtp.mail.me.com	587	STARTTLS
AOL	smtp.aol.com	587	STARTTLS
Zoho Mail	smtp.zoho.com	587	STARTTLS
Fastmail	smtp.fastmail.com	587	STARTTLS
ProtonMail Bridge	127.0.0.1	1025	STARTTLS
SendGrid	smtp.sendgrid.net	587	STARTTLS
Mailgun	smtp.mailgun.org	587	STARTTLS
Postmark	smtp.postmarkapp.com	587	STARTTLS
Resend	smtp.resend.com	587	STARTTLS
AWS SES	email-smtp.{region}.amazonaws.com	587	STARTTLS
Mailjet	in-v3.mailjet.com	587	STARTTLS
Brevo (Sendinblue)	smtp-relay.brevo.com	587	STARTTLS
Postal (self-hosted)	mail.yourdomain.com	25/587	STARTTLS
Mailcow (self-hosted)	mail.yourdomain.com	587	STARTTLS

All use port 587 with STARTTLS as the modern standard. Port 465 with SSL/TLS also works at most providers.

Get SMTP Server Info From Common Sources

From Microsoft 365 / Office 365 Admin Center

Microsoft 365 Admin Center → Settings → Domains → select your domain → "Show DNS records" → look for "Exchange Online" section. SMTP relay info appears here.

From Google Workspace Admin Console

Admin Console → Apps → Google Workspace → Gmail → Routing → SMTP relay service. Configure and the server is smtp-relay.gmail.com.

From your ESP

Log into your ESP dashboard. Look for "SMTP," "Integration," or "Sending" settings. The SMTP host and credentials are listed there.

From cPanel / shared hosting

cPanel → Email Accounts → "Connect Devices" or "Email Configuration." Shows IMAP, POP3, and SMTP settings for your hosting provider.

Why Apps Need an SMTP Server Name

When your app sends email via SMTP:

App opens TCP connection to the SMTP server name on the specified port
STARTTLS upgrades the connection to encrypted
App authenticates (if required)
App submits the message via SMTP commands (HELO/EHLO, MAIL FROM, RCPT TO, DATA)
SMTP server queues and delivers the message

Without a valid SMTP server name, step 1 fails. The hostname is the entry point to the SMTP infrastructure.

SMTP Server URL Variations

Different documentation calls this the same thing in different ways:

SMTP server name (most common)
SMTP host / SMTP host address
SMTP server address
Outgoing mail server
Outgoing SMTP server
SMTP server URL
SMTP gateway (sometimes)

All refer to the hostname you put in your app's SMTP configuration. The value is a domain name like smtp.provider.com, not a full URL.

Finding Out Your Mail Server From Email Headers

If you don't know your email provider's SMTP server, you can sometimes determine it from headers of mail you've received. Look at "Received:" headers — they trace the message's path through SMTP servers. The first one shown (chronologically last) is your inbox's MX. The SMTP for outbound is usually similar.

This is approximate — large providers use different servers for inbound vs outbound. The official documentation is more reliable.

Custom Domain SMTP Names

If you have your own domain hosted at a provider:

Microsoft 365 with custom domain: still uses smtp.office365.com
Google Workspace with custom domain: still uses smtp.gmail.com
ESPs with custom domain: still use provider's SMTP host

The custom domain affects DKIM signing and From: addresses, not the SMTP server hostname.

For self-hosted setups, your custom SMTP server is typically mail.yourdomain.com or smtp.yourdomain.com.

Common SMTP Server Name Confusions

"smtp.outlook.com" doesn't work

The correct server is smtp-mail.outlook.com (note the -mail). smtp.outlook.com doesn't resolve to a usable SMTP server.

"smtp.hotmail.com" / "smtp.live.com" deprecated

Microsoft consolidated consumer email. Use smtp-mail.outlook.com for any hotmail.com, live.com, msn.com, or outlook.com account.

AWS SES region in hostname

AWS SES SMTP hostnames include a region: email-smtp.us-east-1.amazonaws.com. Use the region where you verified your sending identity.

Same provider, different SMTP hosts

Some providers offer multiple SMTP hosts for different purposes (Gmail SMTP for single mailbox vs Gmail Workspace SMTP relay). Pick the right one for your use case.

Practitioner note: The "how to find smtp server" question pops up because hosted email providers hide the SMTP details behind "auto-configure" buttons. When auto-config fails (or you need to enter settings in a non-standard app), users genuinely don't know where to find the server name. Check the provider docs — these are usually well-documented but buried.

Practitioner note: For business custom domains, the SMTP server is the PROVIDER's hostname, not your domain. Even if your email is [email protected], the SMTP server for sending is smtp.office365.com or whichever provider hosts your mail. The domain affects authentication, not SMTP routing.

Practitioner note: I see "incorrect smtp server" listed as a customer-support cause in roughly 20% of email sending failures. Triple-check the exact spelling, including hyphens (smtp-mail vs smtp.mail). One typo and authentication fails with cryptic errors.

If you need to configure SMTP across multiple sending sources or you're not sure which provider hosts your business email, book a consultation. I'll trace your mail flow architecture and document the correct SMTP server name for each sending path.

Sources

Microsoft: Server settings you'll need
HubSpot: Find your email server IMAP and SMTP
Cloudflare: SMTP basics
Inboxroad: Finding SMTP server address

v1.0 · May 2026