530 Authentication required

Question

SES has started to reject some of my outbound emails with the error: 530 Authentication required

```
This message was created automatically by mail delivery software.

A message that you sent could not be delivered to one or more of its
recipients. This is a permanent error. The following address(es) failed:

host email-smtp.us-east-1.amazonaws.com [18.210.31.252]
    SMTP error from remote mail server after MAIL FROM::
    530 Authentication required
```

Other emails still go through fine though. I have only one set of SES credentials and they have not changed. This looks like an issue at AWS.

HMOF · Answer

The problem is that TLS negotiation is timing out, so my server tried to send the email without authenticating itself. I forced my server to require TLS for email-smtp.us-east-1.amazonaws.com so that it won't try to send the email unauthenticated.

But the TLS shouldn't be timing out, this looks like an issue at AWS.

530 Authentication required

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