Definition
💡 A Simple Mail Transfer Protocol (SMTP) is a protocol that facilitates the sending and relaying of emails. It lets you send and receive personal or bulk emails. Without it, you can’t send outgoing messages.
Example
When you send an email from address A to address B, it reaches your SMTP server first. From there, the server identifies the recipient’s server address and then relays your message to its final destination (address B).
What is an SMTP server for Gmail?
The SMTP server for Gmail is smtp.gmail.com. Google recommends using the SMTP relay service if you are planning to send emails using a device or app. It is capable of authenticating messages with IP addresses and is the most secure option.
What is an SMTP server in Outlook?
The SMTP server in Outlook is configurable. Depending on how you customize its settings, you can send or receive emails from different email clients, not just Outlook email addresses. The server address is smtp-mail.outlook.com. The port should be 587 (with Transport Layer Security or TLS). Meanwhile, the encryption should be STARTTLS.
Which port is used to connect to an SMTP server?
Ports serve as addresses or virtual locations that help identify a network service. There are several key SMTP ports to keep in mind if you are planning to connect to an SMTP server:
- Port 25
- Port 465
- Port 587
Note that Ports 25 and 465 are considered outdated. Port 25 was introduced in the 1980s, and today it is widely used by spammers because it supports open relay. Meanwhile, Port 465 was previously recognized by the Internet Assigned Numbers Authority (IANA) as valid. However, it was deprecated with the introduction of the new STARTTLS protocol command.
Port 587 is now known as the “default” port. Paired with TLS encryption, Port 587 helps ensure that your emails are submitted securely and are compliant with the Internet Engineering Task Force (IETF) guidelines.
How to find the SMTP server name and port
There are several ways to do this:
- If you are using an email client like Outlook or Thunderbird, you can find the server information under your Account or Outgoing Server Settings.
- Contact your mail service provider or system administrator if you are using your company’s email service.
- Check your mail provider’s help center for technical documentation or resources if you’re using web-based email services like Gmail or Yahoo Mail.
