Use ses to send all emails to gmail to the dustbin

Dear Amazon,

We found some problems when using AWS SES service and we shall be grateful if you could help us solve the following problems together: We have counted the data of emails sent by SES since 2020. Among them, the open rate of emails sent to Gmail is less than 1%, and most of them are in the spam folder. While the same email sent to yahoo Mail was opened 20% of the time. Therefore, we tested emails using different outboxes, IP addresses, and email content mainly for Gmail.

Here are some of the tests listed:

1. Mail goes all into the spam folder when sending to the Gmail address using the subdomain: newsletter@wantdo.com and newsletter.wantdo.com
2. Part of the mail goes into the spam folder when sending to Gmail address by using the default domain: newsletter@wantdo.com and us-west-2.amazonses.com
3. Mail goes all into the spam folder when sending to newly registered Gmail address using newsletter@wantdo.com and us-west-2.amazonses.com
4. We sent mostly plain text emails in this test. But unfortunately, they all went to the spam folder.

With our statistics attached, we have the following questions:

1. The opening rate of Gmail is very low, whether it is related to Amazon's email sending channel?
2. Could you help us apply for a Gmail whitelist to get our mail through instead of going to the bin.
3. Is there any other better solution to help us solve the problem of low opening rate of Gmail?

Please let us know what should be done to reinstate our account. Your help is much appreciated. Looking forward to hearing from you.

Best, Wantdo