Question Error SMTP (220):Authentication Failed

[David W]

Hi everyone
Sorry for I haven't a fluency english

I'm starting to a new webserver with plek 12.5
OS Debian 8.0‬
Version de Plesk 12.5.30 Mise à jour n° 45, dernière mise à jour à 31 Aoû 2016 23:47
PHP version 5.6.24 os vendor
I have Try all version but there's no difference about error in Roundcube

For Mail -> Postfix and Roundcube

All working fine ...but when I'ms sending a new mail i have the error SMTP 220 authentification

I have read a lot of post about error 250, 220 but no one of them solve my problem

I have look for TLS and port used by, (587) normally fine, but I don't know where the erros is

Have you got an idea about