HttpRequest Converting > to?

Question

I am using code (see below) that I found for sending an AWS SES message with an HttpRequest to amazon. I am able to send MIME messages with PDF attachments and all has been great.

Today, I tried changing from text/plain (in my body) to text/html, and added div tags, so that I could add some formatting to the emails.

Unfortunately, somewhere along the way, the '>' character in the tags is getting converted to '?', which breaks the html. This only happens to about one in three instances and I cannot tell what factor determines whether the '>' remains as '>' or shows up in the email as '?'.

I have taken the base 64 encoded value from this line and run it through web based decoding tools, and it appears to be fine:

EncodingUtil.base64Encode(Blob.valueOf(body)).replaceAll('=','%3D')

Are there any known complications with HttpRequest posts that might be responsible for breaking the html tags?

String emailRequest = 'Action=SendRawEmail';
emailRequest += '&RawMessage.Data=' + EncodingUtil.base64Encode(Blob.valueOf(body)).replaceAll('=','%3D');

AWSHelper helper = new AWSHelper('us-east-1','ses');
helper.sendEmail(Blob.valueOf(emailRequest));

---

private String httpMethod = 'POST';
public void sendEmail(Blob mimeMessage) {
    Map<String,String> queryParams = new Map<String,String>();
    Map<String,String> headerParams = new Map<String,String>();
    headerParams.put('content-type','application/x-www-form-urlencoded');
    headerParams.put('content-length', String.valueOf(mimeMessage.size()));
    headerParams.put('date',requestTime.formatGMT('YYYYMMdd\'T\'HHmmss\'Z\''));
    headerParams.put('host',new URL(awsSESEndPoint).getHost());

    HttpRequest request = new HttpRequest();
    request.setMethod(httpMethod);
    request.setBodyAsBlob(mimeMessage);
    request.setEndpoint(awsSESEndPoint);
    for(String key: headerParams.keySet()) {
        request.setHeader(key, headerParams.get(key));
    }
    request.setHeader('Authorization',authorizationHeader(mimeMessage,queryParams,headerParams));

    HttpResponse response = new Http().send(request);
    if(response.getStatusCode() == 200) {
        ResidentCommonFns.addPageMessage('Successfully Sent Email','Confirm');
    } else {
        ResidentCommonFns.addErrorMessage(response.getBody());
    }
}

Answer 1

.replaceAll('=','%3D') should instead be EncodingUtil.urlEncode(... ,'utf-8'). This will make sure that all characters are properly encoded.