Story: Send email to a unique email id and SES will receive it and store it in the S3 bucket as a PDF file.

I followed aws article (https://aws.amazon.com/premiumsupport/knowledge-center/ses-receive-inbound-emails/#) and updated the DNS configuration using aws article (https://docs.aws.amazon.com/ses/latest/DeveloperGuide/receiving-email-mx-record.html). When i try to enter the simple record it was error out "record type is already exist".

We are hosting our website from aws, and using office365 email server. I see we have one MX record for office 365 email server in Route 53 with the value 0 xxxxxxl-com.mail.protection.outlook.com.. My question is how I can add 2nd MX record for the same domain in Route 53 to for SES to receive inbound emails?.