SPAM checking/detecting/filtering #99

[peterhough]

Implemented Tharit's code from #99
Included tests and config option.

[peterhough]

Having slept on this - an improvement could be that the config allows you to specify which spam checks to fail on e.g. Spam & Virus only.

Also, is throwing an error the right action? People might have CloudWatch Alarms for errors.

Guidance appreciated.

[arithmetric]

@peterhough, thanks for this contribution. It looks good, and I will give it a try.

I like your idea to allow configuration of the spam checks that block the message. The verdicts list with all of the checks is a good default if no configuration is given.

Also I agree that if a spam message is blocked, it would be better not to trigger the same type of error thrown for unexpected failures. To silently discard messages that do not match a forwarded address, the transformRecipients function uses return data.callback(); to call the Lambda's callback function to signal completion of the script.

[ajhodges]

Just wondering about the status of this PR. @peterhough did you have any thoughts on that feedback? I'd personally love to get this merged so I'm willing to take over the PR if you've run out of bandwidth.

[peterhough]

Hi @ajhodges

Thanks for the nudge; the feedback all makes sense to me. Those tweaks just need to be implemented and tested.

At the moment I'm on a limited development environment so if you're happy to pick this up I'm more than happy for you to pick this up.

Cheers

[cbschuld]

@peterhough thx for this update; I ended up taking Joe's great work here and updated it to be TypeScript and set it up to be released via the AWS CDK if you are interested (https://github.com/cbschuld/aws-lambda-ses-forwarder-cdk).