On 2019-10-18, Richard Kettlewell wrote:
>Can you see what happens in the SMTP connection? At the least you need
>to establish whether Exim is attempting to authenticate and failing, or
>not even trying.

FWIW I've seen perfectly standard email to gmail.com addresses
rejected with this specific error in the last few weeks. It's just
gmail being big enough not to have to care.

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