They have won. I cannot use a custom SMTP server for my user registration

Question

I have tried to have my SMTP server with exim4 for a while to send ecommerce registration and transaction confirms.

I followed all the good rules, like SPF, DKIM, DMARC, SMTP encryption. The postmaster tool by google said the IP has a good reputation and there are not spam traffic.

I reached a antispam test result of 10/10 using https://www.mail-tester.com/ or some similar tools.

But everything was not enough, my ecommerce registration messages are sent to spam by Gmail and it is the same with some other famous providers. I have understood I can't do nothing against.

Then, what is a good solution for user registration for an ecommerce? How can I reduce the messages delivered to spam folder?

Answer 1

Here is something you can try that may help.

1. Use a 3rd-party delivery provider (AWS SES, SendGrid, Mailgun) with a Good IP reputation. Here's a list of places you can check their IP reputation https://www.helloinbox.email/#reputation (Talos and Barracuda).
2. Use a subdomain to send transactional emails (email.example.com).

Let me know if that doesn't work.

Answer 2

I'm afraid you haven't provided enough information to identify the problem. Hundreds of factors can contribute to deliverability outcomes; it's not as simple as setting up authentication, reverse DNS, etc. In addition, no free mail tester can accurately tell you how your deliverability will be at Gmail, Outlook, Yahoo, etc., because mail testers don't have the same data those ISPs use to make spam filtering decisions.

If you want more reliable deliverability, it's generally easiest to use a transactional email service to send email, rather than trying to run an SMTP server yourself. There are occasional exceptions to this, but because most senders will have an easier time using one of these services, it's almost always the first thing to try.

(How do email services provide better deliverability? A number of ways, but I think the biggest difference is that they can more closely manage the email sending reputation of their IP ranges. Having anti-spam systems built into the service enables them to resolve problems that much faster, compared to hosting providers which tend to have fewer tools and less data available to stop spammers, so their IP ranges' sending reputation is usually worse.)