Aruba.it (@custom-domain.ext) settings

For @aruba.it and @technet.it mailbox formats go here:
@aruba.it and @technet.it IMAP, POP3, SMTP settings

POP3

Server: pop3s.aruba.it
SSL: true-implicit
Port: 995 (default)
User :  email address (e.g.: name@aruba.it or name@technet.en)

using (Pop3 client = new Pop3())
{
    client.ConnectSSL("pop3s.aruba.it");
    client.UseBestLogin("user@custom-domain.ext", "password");

    // ...

    client.Close();
}

IMAP

Server:  imaps.aruba.it
SSL: true-implicit
Port: 993 (default)
User: email address (e.g.: name@aruba.it or name@technet.en)

using (Imap client = new Imap())
{
    client.ConnectSSL("imaps.aruba.it");
    client.UseBestLogin("user@custom-domain.ext", "password");

    // ...

    client.Close();
}

SMTP

Server:  smtps.aruba.it
SSL: true-implicit
Port:  465 (default)
User: email address (e.g.: name@aruba.it or name@technet.en)

using (Smtp client = new Smtp())
{
    client.ConnectSSL("smtps.aruba.it");
    client.UseBestLogin("user@custom-domain.ext", "password");

    // ...

    client.Close();
}