How do I use Gmail SMTP with port 587 on AWS EC2?

问题

I have used Gmail SMTP service with port 587 on the local server and it's working fine.

But it's not working on AWS EC2 instance. So I added SMTP rules on EC2 instance security inbound rules see below image but SMTP port can not be editable.

Now the issue is if your domain does not configure secured connections. Gmail does not offer port 25 in an unsecured connection.

So, there is any way to use SMTP on unsecured connection with 25 port or any other way.

回答1:

I have fixed issue as of now for a development server. Please, not it's not the correct way to a production site.

For sending an email from AWS EC2 using Gmail SMTP service please follow below steps.

1. Edit security group of your EC2 Instance.
2. Edit inbound rules of the security group.
3. Add 587 port in inbound rules. See below image.

you need to set your instance inbound rules for coming mail and outbound for send.

After that, you can send email using 587 SMTP port from AWS EC2.

Please read this article. https://support.google.com/accounts/answer/6010255?hl=en

https://myaccount.google.com/lesssecureapps

回答2:

According to Googles documentation, you can use the G Suite SMTP relay service through port 25. You can read more information here:

https://support.google.com/a/answer/176600?hl=en

and here:

https://support.google.com/a/answer/2956491

Hope this helps!

回答3:

To send email from C# hosted on Amazon EC2, make sure you have two things done.

1. Use following setting in your Web.config

<mailSettings>
      <smtp deliveryMethod="Network" from="<from email goes here>">
        <network host="smtp.gmail.com" port="587" enableSsl="true" userName="email id goes here" password="<password goes here> />   
      </smtp>
    </mailSettings>

2. Login the above gmail account onto the Amazon EC2. If you do not login, then gmail blocks the email being sent from code due to security reasons.

来源：https://stackoverflow.com/questions/45036620/how-do-i-use-gmail-smtp-with-port-587-on-aws-ec2