After choosing an SMTP service, you need to register for it.
Let’s set one of the free SMTP services. In our case, Gmail.
Google’s GMail SMTP server is a free service for anyone who has a GMail account. If you don’t have a Gmail account, you can create one at the Gmail account creation page.
When you’ve created the account, you’ll need to configure your mail client to use Gmail for the outgoing mail server. As an example we’ll describe the configuration of the Thunderbird mail client.
1. Download Mozilla Thunderbird and install it on your computer.
2. Open it and go to Tools > Account Settings.
3. Under the Account Actions dropdown at the bottom left side, select Add Mail Account.
4. Enter your name in the given box. Write your email address and password in the required fields and click on the Continue button.
5. Thunderbird will try to configure your settings automatically. We suggest to fill in the settings manually, so click on the Stop button on the right.
6. Then click on Manual Setup button to fill in the settings manually.
7. Click on Outgoing Server (SMTP) on the left pane. Select smtp.gmail.com (Default) from the list and click on the Edit button.
8. A small SMTP Server window will appear. Now enter the settings given below:
Outgoing Mail (SMTP) Server: smtp.gmail.com
Use Authentication: Yes
Use Secure Connection: Yes (this can be TLS or SSL depending on your mail client)
Username: your GMail account, e.g. email@example.com
Password: your GMail password
Port: 465 or 587
If you use Google Apps with your domain name, you should write that email account with the Username: field, e.g. firstname.lastname@example.org
9. On the left, click on the first option, i.e. the name of your email (email@example.com). On the right side, fill in your email address in the Account Name field. In the Outgoing Server (SMTP) dropdown, select the server setting you configured in step 8. Click OK.
To configure SMTP plugin, please refer to this article.