The main point of this pull request
By default SNS is able to process email with size less or equal 150Kb (the size is calculated with images, headers, text body). To be able to accept emails with big images you must to setup flow, when email body is uploaded to the S3 and to the server the information where to find that email content will be posted. So the flow for such cases will be a little different: there is no content in the payload, you must to read it from S3 file instead. Flow with S3 has own limitations: your email can has maximum size 30Mb.
What have done:
The main point of this pull request By default SNS is able to process email with size less or equal 150Kb (the size is calculated with images, headers, text body). To be able to accept emails with big images you must to setup flow, when email body is uploaded to the S3 and to the server the information where to find that email content will be posted. So the flow for such cases will be a little different: there is no content in the payload, you must to read it from S3 file instead. Flow with S3 has own limitations: your email can has maximum size 30Mb.