Adding your email to Outlook with SMTP lets you send messages securely through your preferred email provider. Whether you’re connecting a business account, custom domain, or third-party mailbox, understanding SMTP setup keeps your emails flowing smoothly.
Here, you’ll learn how to add and configure SMTP settings on Outlook desktop, web, and mobile, plus how to fix common connection errors if something doesn’t work the first time.
What is the SMTP email server for Outlook?
SMTP stands for Simple Mail Transfer Protocol, and it’s the standard method for sending outgoing emails. It works alongside IMAP or POP, which handle incoming mail. SMTP is what allows your email client, like Outlook, to send messages through your email provider’s server.
When you hit “Send,” Outlook communicates with your SMTP server to deliver the message to the recipient’s inbox. Without proper SMTP configuration, emails may fail to send or appear as drafts that never leave your Outbox.
Correct SMTP setup ensures secure authentication and encryption, protecting your login credentials and preventing your emails from being flagged as spam. It also helps verify your identity to the receiving server, which improves deliverability and keeps your messages out of junk folders.
Related read: How to create an email account
How to add an SMTP email account to Outlook (desktop)
Outlook’s desktop version offers the most control over your email settings, making it ideal for adding professional or custom-domain accounts.
Follow these steps to add an SMTP email account manually:
- Open Outlook and go to File → Add Account.
- Choose Manual setup or additional server types and click Next.
- Select POP or IMAP → Next.
- Enter your name, email address, and password.
- Under Server Information, choose IMAP or POP for the incoming mail type.
- In the Outgoing mail server (SMTP) field, enter your SMTP host address.
- Click More Settings → Outgoing Server.
- Check My outgoing server (SMTP) requires authentication and choose Use same settings as my incoming mail server.
- Go to the Advanced tab and enter your SMTP port. Use 587 for STARTTLS encryption or 465 for SSL.
- Click OK → Next → Finish.
After saving, Outlook will test your settings automatically. If both sending and receiving succeed, your account is ready to use.
Related read: How to add an email account in Outlook
How to add an SMTP email account to Outlook web
Outlook on the web allows you to connect other email accounts and manage them from a single dashboard. You can add Gmail, Yahoo, or a business domain using SMTP if automatic configuration doesn’t work.
Here’s how to do it:
- Go to Outlook.com and sign in to your account.
- Click the Settings (⚙) icon in the top right.
- Select View all Outlook settings.
- Choose Mail → Sync email.
- Under Connected accounts, click Other email accounts.
- Enter your display name, full email address, and password.
- Select Manually configure account settings.
- Enter your SMTP server name, port, and encryption type (STARTTLS or SSL).
- Save changes.
Outlook will verify your credentials before completing setup. If you use Gmail or Microsoft 365, you may need to enable OAuth or app-specific passwords. These security layers prevent unauthorized access and are often required when two-factor authentication (2FA) is active.
Once connected, Outlook web will send and receive mail through your custom SMTP server, just like a native Outlook address.
How to add an SMTP email account to the Outlook mobile app
Outlook’s mobile app for iOS and Android supports manual SMTP setup for custom domains and third-party email accounts.
Follow these steps:
- Open the Outlook app on your device.
- Tap your profile icon or the Settings (⚙) gear.
- Choose Add Account → Add an email account.
- Enter your email and password, then select Advanced settings.
- Turn on Use SMTP for outgoing mail.
- Fill in your server information:
- SMTP server: smtp.yourdomain.com
- Port: 587 (STARTTLS) or 465 (SSL)
- Authentication: Enabled
- Save your settings and send a test email to confirm it works.
If Outlook doesn’t connect, double-check your port numbers and encryption type. Some mobile carriers restrict certain ports, so switching from 465 to 587 may fix the issue.
Common SMTP settings for popular email providers
Here are a few examples of common SMTP configurations:
- Gmail: smtp.gmail.com (Port 587, STARTTLS)
- Yahoo Mail: smtp.mail.yahoo.com (Port 465, SSL)
- iCloud: smtp.mail.me.com (Port 587, STARTTLS)
- Custom domain: mail.yourdomain.com (Port 465, SSL)
If you’re unsure of your SMTP details, check your email provider’s documentation or contact their support.
Troubleshooting SMTP setup errors in Outlook
Even small typos or mismatched settings can stop emails from sending. Here’s how to solve the most common SMTP problems:
- “Cannot connect to server”: Check your port number and encryption type. Some servers only support one specific combination, such as SSL on port 465.
- “Authentication failed”: Re-enter your username and password carefully. If you’re using Gmail or Yahoo, generate an app-specific password in your account settings instead of your main one.
- Emails stuck in Outbox: Make sure Outlook isn’t in Offline Mode. Also check that your SMTP settings match your provider’s exact details, including case-sensitive host names.
- Duplicate sent emails: Go to your account settings and disable the “Save sent messages in Sent Items folder” option if your provider already handles that automatically.
- Delayed or rejected messages: A mismatch in authentication or encryption can cause your server to throttle outgoing emails. Test with a smaller message and check if antivirus software is blocking connections.
The majority of SMTP errors come from incorrect authentication or encryption mismatches. Double-checking these two details usually resolves most setup issues.
Best practice for using an SMTP account in Outlook
Once your SMTP connection is working, a few good habits can help keep your account secure and stable.
- Use app-specific passwords. If your provider supports two-factor authentication, create a unique password for Outlook. This keeps your primary login protected.
- Review your settings regularly. If your domain host changes or you migrate servers, update your SMTP details immediately to avoid sending errors.
- Avoid public Wi-Fi. Public networks can expose your connection to interception. Always use secure connections or a VPN when sending sensitive emails.
- Back up Outlook data. Export your PST files periodically so you can recover sent items and account settings if something goes wrong.
- Use encryption by default. STARTTLS or SSL protects your emails in transit and helps maintain compliance with most business data security policies.
Sorting out server settings or fixing email errors can take up valuable time you could spend on actual work. Fyxer keeps things running smoothly once your Outlook account is set up, so you can focus on the messages that matter instead of chasing down configuration problems.
Fyxer organizes your inbox, drafts replies in your tone, and keeps follow-ups on track, turning a cluttered inbox into something that actually works for you. With Fyxer, you stay in control, communicate faster, and never lose focus to email admin again.
SMTP email account in Outlook FAQs
Can I use the same SMTP settings for multiple Outlook accounts?
You can reuse SMTP settings, but each account needs its own login credentials. For example, two Gmail addresses can share the same SMTP server (smtp.gmail.com) but must authenticate separately. This keeps each mailbox secure and ensures messages are sent from the correct address, avoiding delivery or identity mix-ups. Always verify credentials when switching between accounts to prevent authentication errors.
What’s the difference between SMTP and IMAP?
SMTP handles sending emails, while IMAP manages receiving and syncing them. Outlook uses both to manage two-way communication with your mail server. In practice, SMTP pushes your messages out, while IMAP keeps everything up to date across devices so your inbox looks the same whether you’re on desktop, web, or mobile. Both are essential for a complete email setup that works smoothly and reliably.
Why is my SMTP connection failing?
The most common reasons are an incorrect password, port, or encryption type. Double-check with your provider’s documentation before testing again. Connection issues can also happen if your antivirus or firewall is blocking the port, or if your email provider has temporary restrictions. Testing with another network or device can help identify whether it’s a local or server-side problem.
Do I need SSL or TLS for SMTP?
Yes. Both SSL and TLS (STARTTLS) encrypt your connection, preventing third parties from intercepting your messages or credentials. Using encryption is required by most modern email providers for secure transmission. Always select the strongest option supported by your provider to protect sensitive data and maintain compliance with security standards.
Can I set up SMTP in Outlook without a password?
No. Authentication is required for outgoing mail to prevent unauthorized use of your email address. Without it, most servers will reject your messages or mark them as spam. Using secure, unique passwords or app-specific credentials keeps your account protected while ensuring your messages send successfully every time.
Where do I find my SMTP in Outlook?
Go to File → Account Settings → Server Settings. Under Outgoing Mail (SMTP), you’ll see your server name, port, and encryption method. You can edit them directly if needed. This is also where you can troubleshoot by testing new configurations or updating details after changing your email password or server provider. Keeping this section accurate ensures Outlook always sends mail without delays or errors.