How to prevent email from going to Recipient(Gmail) junk folder?

Gmail already guide the most detail here. However, we need to repeat the most important points that we can do by ourselves to solve such issue.

https://support.google.com/mail/answer/81126?hl=en&vid=1-635789122382665739-3305764358

If your email messages repeatedly go to Gmail junk folder, follow these recommendations:

1. Check if you have Added SPF record for your domain. If you are using our email service and your domain is using our domain name servers, our system should have added it by default. You can check from Control Panel > DNS. If you are using third party name servers, you will need to manually add SPF for your domain from their end. Using our email service, SPF record should be:

v=spf1 a mx include:_spf.site4now.net?all

2. Add DKIM record for your domain. See the guide here: https://www.SharkASP.NET/support/kb/a1781/set-up-dkim-and-domain-key.aspx?KBSearchID=748859.

3. Generate DMARC record online and Add DMARC record for your domain.

https://mxtoolbox.com/DMARCRecordGenerator.aspx

4. Test by send email to your personal Gmail account now.

5. If the issue continues, please contact your Email service provider now.