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# echo -ne "user@example.com" | base64
# dXNlckBleGFtcGxlLmNvbQ==
# echo -ne "PutYourSecretPasswordHere" | base64
# UHV0WW91clNlY3JldFBhc3N3b3JkSGVyZQ==

openssl s_client -starttls smtp -crlf -connect smtp.example.com:587

EHLO test
AUTH LOGIN dXNlckBleGFtcGxlLmNvbQ==
UHV0WW91clNlY3JldFBhc3N3b3JkSGVyZQ==
mail from: <user@example.com>
rcpt to: <mary.doe@example.net>
data
From: John Doe <user@example.com>
To: Mary Doe <mary.doe@example.net>
Subject: Test ESMTP Auth LOGIN
Testing proves the existence of bugs not their absence
.
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