How to Use G Suite SMTP to Send Outgoing Email

As part of the Google Workspace (formerly known as G Suite) configuration of apps, you have access to Gmail. Not everyone who is using G Suite through their organization chooses to use Gmail as the primary email interface, though.

However, if you have another type of email client that you are using for outbound messages, you still can send the messages through Google’s and G Suite’s SMTP, ensuring you have access to all of the security features found throughout Google.

You can use the SMTP from Google for other email clients when you have a paid G Suite account. Configuring the G Suite SMTP settings is a pretty straightforward process, but you do have to have the information entered just right, or you could run into some issues. Here are some suggestions for using the G Suite SMTP settings to send outgoing emails.

Step-by-Step: Setting up G Suite SMTP

For many G Suite users, using Gmail as your SMTP server does not require many steps. However, if you have a more complex setup, you may need to use the SMTP relay service, which we’ll discuss next.

Specific Email Server Information

With your Google Administrator account signed in, click on Settings and Site Settings. Enter the requested information in the Outgoing SMTP Server section of the Email window.

  • Host:
  • Port: 465 (if you’re using SSL encryption) or 587 (if you’re using TLS encryption)
  • Use SMTP Authentication: Most users will want to activate this box
  • User Name: Enter your email address for your Google account
  • Password: Enter your Google account password
  • SMTP Connection Security: Click on the button that has the type of encryption you are using (if any)

Using Less Secure Apps

If anyone in your organization is using an email client that does not have the same type of sign-in security levels that G Suite requires, your account could have a vulnerability when you set up SMTP.

You can turn off access for these less secure apps, meaning they will not have access to the G Suite SMTP settings. Inside your Administrator settings, open the Security screen. Scroll until you see Less Secure App Access. Slide the bar to the on or off position to determine how to handle these less secure apps. (Google recommends turning it off.)

Step-by-Step: Setting up G Suite SMTP Relay Service

Here are the steps to follow to enter the G Suite SMTP settings to route your outbound mail through Google’s SMTP relay service, should you need to set things up this way. (Google recommends that you use the SMTP relay service when you want to determine exactly which devices in the organization will have access to your G Suite SMTP outbound email server for use with third-party email clients.)

Some of the instructions we have included may not be applicable in your situation, depending on the type of email server you are using.

1. Sign in as an Administrator

To make the changes across your entire G Suite organization, you will need to configure the SMTP settings using your administrator account, not your Gmail account. Click the following links in order on the screen that follows:

  • Apps
  • Google Workspace Suite
  • Setting for Gmail
  •  Routing

2. Set SMTP Relay Service

Now, you’ll determine which devices may use SMTP through G Suite.

Look in the Routing section of the page, scrolling down to SMTP Relay Service. Then, click Configure.

3. Select Allowed Devices for Sending

Through this section, you’ll select the users who can send messages through the SMTP by placing limits on who can use it. The options include:

  • Only Registered Apps Users in My Domain: This is a recommended setting to activate, as it ensures that the registered user has to be part of one of your domains to be able to use your SMTP server.
  • Only Addresses in My Domains: This is a setting you should activate when you have apps from third parties that will need to send messages. With this setting activated, the sender doesn’t necessarily have to be a G Suite user, but it does have to be part of your domain.
  • Any Addresses: Google does not recommend activating this setting. It would allow the sender address to be from any device, whether it’s registered as part of your domain or not. This could open you up to malware or other types of attacks

4. Select Encryption Level

You then will need to select the type of encryption that you want to use. First, check to see whether your email server supports TLS (transport layer security) encryption. TLS is a common type of security protocol used in a variety of devices that send and receive data across the internet, but it is possible that your server does not support it.

If your server supports TLS, and if you want to use this type of encryption with your messages in the SMTP relay service, then activate the Require TLS Encryption box.

If your server does not support TLS, do not activate the box, or Google will reject any non-encrypted messages, causing significant problems for your system.

Some SMTP servers may use SSL (secure sockets layer) encryption, so you may have this option available.

Finally, click Save to finalize your settings. You should see these new settings choices on the Advanced Settings or Routing page. Click Save at the bottom of the page to finish the process.

It can take up to 24 hours for these new G Suite SMTP settings to become active.

5. Set Up the Outbound Email Server to Work With Google

Now you’ll want to set up your email outbound server to go through the G Suite Gmail settings, even when you’re using other email clients. The following steps will work in most SMTP relay service situations, but you may need to use different settings, depending on the type of outbound email server you’re using.

Server Address

Use as the address for the on-premise outbound email server.


The port you’ll select depends on whether you are using SSL or TLS encryption (as we discussed earlier).

  • If you are using TLS encryption, you will need to use port 587.
  • If you are using SSL encryption, you will need to use port 465.
  • If you are not using any encryption, you can use port 25, 465, or 587.

When to Configure the G Suite SMTP Settings By Hand

You will want to set up your G Suite account and Gmail with SMTP settings when you want to manage your outbound email server yourself to accept email clients other than Gmail.

Occasionally, some third-party email clients may be able to reconfigure the SMTP settings for you, but if you end up with error messages, you’ll have to make the changes by hand.

Taking Advantage of Google’s Features

One of the best reasons to route all of your emails through the Google SMTP settings is so you can gain access to all of Google’s email settings, which provide high levels of security, without having to use Gmail to gain access to them.

People also choose to use Google SMTP because they want all of the emails they send and receive from any connected email client backed up on the Google servers.

When you send emails, if you frequently find that the recipient’s ISPs are blocking the emails you send from other email clients, because those clients use port 25, going through Google SMTP eliminates this problem because it does not have to use port 25. You have a couple of other options for the port. (Some ISPs block messages from port 25 because when an attacker takes control of an email account and sends spam, it goes through port 25.)

What Is SMTP?

SMTP is short for simple mail transfer protocol. Without this protocol, networks would be unable to deliver your outgoing email messages, as the network would not know the intended destination nor how to make the messages arrive properly.

SMTP is one of those acronyms that most people don’t think about or use regularly, but, like many other protocols, it ensures that your ingoing and outgoing data have the proper routing.

Like other protocols, SMTP is made to operate without regular intervention from users or administrators. You only need to pay attention to SMTP when you’re trying to troubleshoot an issue or when you need to change the way it is working by reconfiguring the settings.

Understanding the SMTP Protocol

In technical terms, SMTP is an application layer that exists in TCP/IP (short for transmission control protocol and Internet protocol). TCP/IP is the set of communications protocols that allow the Internet and other types of computing networks to operate.

SMTP works in conjunction with the MTA protocol (or mail transfer agent) to ensure that email messages properly leave your Gmail account and move through various networks until they reach the intended recipient. The SMTP tells MTAs exactly how to deliver the message.

None of this requires intervention on your part. SMTP handles everything behind the scenes.

Nuts and Bolts of SMTP

When you send an email, the network breaks up the message into multiple chunks of text. This speeds up passing the data along the network, as sending multiple small chunks goes faster than sending a single, large message.

SMTP places codes at the end of each chunk of text, and these codes allow the email server that receives the message to put it back together so the recipient can read it.

Sending Graphics

SMTP does not handle any graphics or other non-text items you are sending in an email message. SMTP doesn’t even handle formatting changes to text, such as italics or different fonts. (It is a “simple” protocol, after all.)

When your email messages have non-text items as part of them, SMTP teams up with MIME (multipurpose Internet mail extensions) to handle these items. MIME encodes all of the graphics and font selections into plain text, allowing SMTP to handle them. Once the message arrives, the email server that receives the message uses MIME again to put the graphics back together.

Making Use of SMTP

Fortunately, you don’t have to worry about the exact way SMTP handles your emails. As long as you properly configure the G Suite SMTP settings initially, SMTP will handle the process of moving your outgoing email messages along seamlessly, regardless of whether you choose to use Gmail as your primary email client, or whether you want to use another email client.

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Bryan Wise
Bryan Wise,
Former VP of IT at GitLab

Incredible companies use Nira