Anyway that error is related to the SSL protocol version the client and the server are trying to negotiate. See [here](http://openssl.6102.n7.nabble.com/quot-SSL3-GET-RECORD-wrong-version-number-quot-td8310.html) for example. I think it little nothing to do with Nim SSL wrapper, you could try to connecto with curl with a command like this curl --url 'smtps://smtp.office365.com:587' --ssl-reqd --mail-from 'usern...@gmail.com' --mail-rcpt 'j...@example.com' --upload-file mail.txt --user 'usern...@gmail.com:password' --insecure
and check if you obtain a different result
