How do I know what my outgoing mail server is? You need to check your email account’s SMTP (Simple Mail Transfer Protocol) settings in your email client or webmail configuration. The outgoing mail server is listed as the “SMTP server” in your account settings, and you can also identify it by viewing the email message headers of a sent email. In most cases, it looks like smtp.yourprovider.com, such as smtp.gmail.com or smtp.office365.com. By accessing your email settings or inspecting message headers, you can quickly determine which outgoing mail server is being used.
Now let’s explore this in depth so you can confidently identify your SMTP server for troubleshooting, setup, or security purposes.
What Is an Outgoing Mail Server?
An outgoing mail server is the server responsible for sending your emails. It uses SMTP (Simple Mail Transfer Protocol) to transfer messages from your device to the recipient’s mail server.
When you click “Send”:
- Your email client connects to the SMTP server.
- The server authenticates your login credentials.
- The message is routed to the recipient’s mail server.
- The recipient receives the email.
Without a correctly configured outgoing mail server, emails cannot be sent.
Common Examples of Outgoing Mail Servers
Here are some typical SMTP servers used by popular email providers:
- Gmail → smtp.gmail.com
- Microsoft Outlook / Microsoft 365 → smtp.office365.com
- Yahoo Mail → smtp.mail.yahoo.com
- Hosting provider → mail.yourdomain.com
If you use a custom domain like [email protected], your outgoing mail server might be provided by your web hosting company.
Method 1: Check Your Email Client Settings
The easiest way to find your outgoing mail server is to check your email account settings.
In Outlook
Steps:
- Open Outlook.
- Click File → Account Settings → Account Settings.
- Select your email account.
- Click Change.
- Look for the outgoing mail server (SMTP).
You will see the SMTP server address listed there.
In Thunderbird
Steps:
- Open Thunderbird.
- Go to Account Settings.
- Scroll down to Outgoing Server (SMTP).
- Check the Server Name field.
This shows your outgoing mail server.
On Mobile Devices (Android or iPhone)
- Open Settings.
- Go to Mail or Accounts.
- Select your email account.
- Tap Outgoing Mail Server.
- The SMTP address will be displayed.
Method 2: Check Email Headers (Most Accurate Method)
If you don’t have access to account settings, you can check the email headers of a sent message.
Email headers show the technical path your message traveled, including the sending SMTP server.
In Gmail
Steps:
- Open a sent email.
- Click the three dots (⋮).
- Select Show original.
- Look for lines starting with:
Received: from
The first “Received” entry typically shows the outgoing SMTP server.
Example:
Received: from smtp.gmail.com
This confirms Gmail’s SMTP server was used.
Method 3: Check Your Hosting Provider
If you use a business email like [email protected], your outgoing mail server may be provided by:
- cPanel hosting
- VPS server
- Cloud email service
Log into your hosting dashboard and check:
- Email Accounts section
- Mail configuration
- SMTP settings documentation
It may look like:
- mail.yourdomain.com
- server123.hostingprovider.com
Method 4: Check WordPress or Website SMTP Plugin
If you’re sending emails from a website:
- Log into WordPress.
- Run to your SMTP plugin (e.g., WP Mail SMTP).
- Look at the SMTP Host field.
It will show the outgoing server being used.
This is especially important for ecommerce stores, contact forms, and automated email systems.
How to Identify SMTP Server by Email Address
Sometimes the domain gives you a clue:
- @gmail.com → smtp.gmail.com
- @outlook.com → smtp.office365.com
- @yahoo.com → smtp.mail.yahoo.com
However, this is not always accurate for business emails with custom domains.
What About SMTP Ports?
When checking your outgoing server, also verify the port number:
- 587 (TLS) – Recommended
- 465 (SSL)
- 25 (Often blocked by ISPs)
Correct port + correct SMTP server = successful email sending.
Why Knowing Your Outgoing Mail Server Is Important
You may need this information to:
- Fix “cannot send email” errors
- Configure a new email client
- Set up a website contact form
- Improve deliverability
- Configure SPF, DKIM, DMARC
- Troubleshoot authentication problems
Without knowing your SMTP server, proper configuration is impossible.
Common Problems When Identifying SMTP Server
1. Multiple Accounts
You may have several email accounts configured. Make sure you’re checking the correct one.
2. Webmail Only
If you only use browser-based email, settings may not be visible. Use headers instead.
3. Custom Business Setup
Some companies use email relays or third-party services, so the SMTP server may differ from the domain name.
Security Tips
When checking your outgoing mail server:
- Never share your SMTP password publicly.
- Enable two-factor authentication.
- Use app passwords when required.
- Avoid port 25 if possible.
- Regularly monitor sent mail activity.
If you discover an unfamiliar SMTP server in headers, it may indicate unauthorized access.
Quick Checklist
- Open email account settings
- Look for “Outgoing Mail Server (SMTP)”
- Verify server name
- Confirm port number
- Check encryption (SSL/TLS)
- Test sending email
Final Thoughts
To know what your outgoing mail server is, simply check your email client’s SMTP settings or inspect the headers of a sent message. The outgoing mail server is responsible for delivering your emails and is usually labeled clearly in account configuration settings.
Whether you’re troubleshooting errors, configuring a new device, setting up a website, or improving email security, identifying your SMTP server is a fundamental step. Once you know the server name, port, and authentication method, you can ensure reliable and secure email delivery across all platforms.
Understanding your outgoing mail server gives you greater control over your email system — and helps prevent sending failures, spam issues, and configuration mistakes.
