'Incorrect greeting' usually means the authentication method in TB is wrong, or the password or User Name. [https://assistenzatecnica.tim.it/at/portals/assistenzatecnica.portal?_nfpb=true&_pageLabel=MailBook&radice=consumer_root&nodeId=/AT_REPOSITORY/630002 According to their site], the outgoing server should be mail.tin.it on port 587 with connection security = none and authentication = no authentication. This might work if you're connected to the TIM network, but probably not through a non-TIM network, which might explain 'access denied'.