try to use SES in Soto SDK with Vapor 4 but I have some error about soto HOT 2 CLOSED

Are you creating your AWSClient with httpClientProvider set to .createNew and when calling SES methods setting eventLoop to req.eventLoop? If so you are asking the HTTP client to run on an EventLoop from a different EventLoopGroup.

If you want to use the request event loop you need to use an HTTP client that uses the same EventLoopGroup. Luckily Vapor provides one. I believe you can get it via app.client.shared. You should then create your AWSClient as follows

let awsClient = AWSClient(httpClientProvider: .shared(app.client.shared))

from soto.

Converting this to a discussion, as it is not an issue

from soto.