ASP.NET MVC 5 - SMTP Email Notification

Notifications to end-users are a very crucial need for interactive web development. Popular forms of notifications in web development are emails and SMS alerts. It is essentially a responsibility of the websites (that are maintaining end-user accounts) to notify end-users about various interactions happening with their accounts, simply, to feel more secure, more aware, and more in control of their accounts with third-party products.

Prerequisites

Following are some prerequisites before you proceed any further in this tutorial:

1. Knowledge about ASP.NET MVC5.

2. Knowledge about HTML.

3. Knowledge about Javascript.

4. Knowledge about AJAX.

5. Knowledge about CSS.

6. Knowledge about Bootstrap.

7. Knowledge about C# programming.

8. Knowledge about C# LINQ.

9. Knowledge about JQuery.

Since I am going to use a Gmail account as a source email address for sending email notifications, hence, I will be using "smtp.gmail.com" as my host type configuration with port "587" which are essential configuration properties for SMTP protocol. You can use "587" port for other common email host types as well. Below are the list of host type configuration for other common email host types i.e.

1. GMAIL SMTP HOST -> smtp.gmail.com

2. YAHOO SMTP HOST -> smtp.mail.yahoo.com

3. HOTMAIL/LIVE SMTP HOST -> smtp.live.com

4. OUTLOOK/Exchange Server SMTP HOST -> smtp-mail.outlook.com

In order to send email notifications from your website to end-users of your web product, you need to have a source email account. The concept is simple here, you need an email account to send a notification to another email account. The only difference is that your source email account should not be your personal account, so, it cannot be misused. For example, when you receive email notifications from your social media accounts, notice that they specifically write "do-not-reply" in the name of the email address or mention that at the end of the email notifications that not to reply to this email address. The reason is simple they have fixed that particular email account for sending notifications only, according to the actions you perform on their websites. So, here below are the mandatory configuration properties within your code to configure your source email address for sending email notifications to the end-users i.e.:

1. FROM_EMAIL_ACCOUNT

2. FROM_EMAIL_PASSWORD

3. SMTP_HOST_TYPE

4. SMTP_PORT

   
   

ERROR EXPECTED

Type recipient email address and press "Send Notification" button, you will see "The SMTP server requires a secure connection or the client was not authenticated. The server response was: 5.5.1 Authentication Required. Learn more at" error i.e.

There are two main reasons for the above error:

1. I am using localhost and not SSL enabled certificate i.e. "https://".

2. I am using Gmail account as source email address and Gmail account explicitly requires access permission for logins outside Gmail client.

Even if you enable SSL certificate, you will still see the error because of Gmail explicit permission settings. The above error happens only for Gmail not by other providers. Gmail will also send you an email about sign-in attempts

So, in order to enable access permission for gmail account, perform the following steps:

1. Login to your Gmail account from the web browser.

2. Go to "https://myaccount.google.com/lesssecureapps" link.

3. Turn "Allow less secure apps" property "ON".

Conclusion

In this article, we learned  how to send an email notification to the recipient email address from our website. We leamed about SmtpClient library and different configuration settings in order to send the email notification. We saw SMTP protocol host types for different common email providers. You also learned to resolve the source Gmaill account sign-in issue outside the Gmail client and allow sign-in access to less secure apps for your source Gmail account.