What is SMTP Server? How to Fix SMTP Server Settings for Gmail?

How to Configure SMTP Server for Gmail

SMTP servers are complex, and if you just immerse your toe in how the email is sent-sent world, it’s easy to feel overwhelmed. We’ve put together a list of the most common SMTP server questions we’ve received so we can help you send email, so you’re an SMTP expert in an instant.

What is an SMTP server?

A Simple Mail Transfer Protocol (SMTP) server is an application whose primary purpose is to send, receive, and / or forward outgoing mail between email senders and recipients.

An SMTP server has an address (or addresses) that your e-mail program or application can set, and is usually formatted as smtp.serveraddress.com. (For example, the Gmail SMTP server address is smtp.gmail.com and the Twilio SendGrid is smtp.sendgrid.com. You can usually find the SMTP server address in the account or settings section of your email program.)

When you send an e-mail, the SMTP server processes your e-mail, decides on the server to which the message will be sent, and forwards the message to that server. The recipient’s mailbox service provider, such as Gmail or AOL, then downloads the message and places it in the recipient’s mailbox.

You can find more information about SMTP servers on our document page.

Is the SMTP server the same as a normal server?

Technically yes. Like most servers, an SMTP server processes data to send to another server, but it has a very precise purpose to process information related to sending, receiving, and forwarding e-mail. Also, the SMTP server may not be on the machine. It is an application that is constantly running while waiting to send new mail.

Why are SMTP servers important?

Without an SMTP server, your email would not reach its destination. When you click “send”, your email will change to a code string, which will then be sent to the SMTP server. The SMTP server is able to process that code and forward the message. If the SMTP server was not present to process the message, it will be lost in the translation.

In addition, the SMTP server verifies that the outgoing e-mail is from an active account, which serves as the first protection to protect the mailbox from illegal e-mail. It will also send the email back to the sender if it cannot be delivered. This notifies the sender that they have the wrong email address or that the receiving server is blocking their email.

To learn more about SMTP, check out our post, SMTP Service Crash Course.

What does the SMTP server do when I send an email with Twilio SendGrid?

1. The e-mail program connects to the Twilio SendGrid SMTP server via smtp.sendgrid.net port 25 (by default).
2. Your email program is having a conversation with our server. First, verify that the username and password used for authentication match the active account, and then forward message information, such as the sender’s address, recipient, and message content.
3. Our server receives the message information collected by your request and then repeats the conversation used in step 2 with the recipient’s email server.
4. The recipient’s e-mail server checks the sending address, the recipient’s address (to make sure he or she is a valid recipient), and the content of the message. It checks the sending domain for possible DNS problems, such as invalid DKIM and SPF signatures. As long as there are no problems, the recipient’s mail server will use POP3 or IMAP to retrieve e-mail and send the message to the intended recipient.

See the diagram below for a visual illustration of the SMTP e-mail delivery process.

Does Twilio SendGrid have an SMTP server to test?

Twilio SendGrid offers free accounts that do not even require a credit card to set up. With a free Twilio SendGrid account, we give you access to the Twilio SendGrid SMTP server and allow you to send up to 100 emails a day. Active free account customers can use their account to send test messages and test email deliverability before updating and sending larger amounts of email.

Do I need to configure the Twilio SendGrid SMTP server for Gmail before sending email?

No! All you need to do is have an active Twilio SendGrid account and the ability to use basic username and password authentication in your email program or application.

Which SMTP server port do I need to connect to?

We support unencrypted and TLS encryption on ports 25, 587, and 2525. To enable SSL encryption, use port 465. Here is more information about sending SMTP e-mail with Twilio SendGrid.