How to avoid my sent email not to be classified as spam?

Question

I work on a website that can send invitations to other people. I ran into a problem that emails sent from my website are classified as spam at major email service providers, I'm just wondering how I can avoid this as much as possible.

Basically what I'm doing now:

1) User login email address

2) I use python to send email, email is simple - clear text, just a string of words to tell people that your friend is inviting you, and the website has created an account for him, password - * *

3) "from" the letter - this is the user who sends the invitation (I wonder if this contributes to the creation of spam?), And not on my website.

Thanks. Bin

Answer 1

Yes. Your third point is the main reason you fall for spam. You send emails with addresses from another domain, and then to the domain of your server, and you change which email address it is all the time. This is a typical behavior of spammers.

Answer 2

• How to send emails and avoid classifying them as spam will give you some useful tips.
• Ways to Prevent Email Blocking as Spam