I read many post about this problem and i can't find a solution for me.
My H0-ECOM100 setup:

Image:
http://clip2net.com/s/6uQ0PxSMTP Viewer log :
SMTP Server : mail.speedy.com.ar or 208.84.244.49
Mon Dec 30 14:04:17 2013 192.168.1.23: Recipient: surbyte@gmail.com
Mon Dec 30 14:04:17 2013 192.168.1.23: Subject: Test EMail from ECOM100
Mon Dec 30 14:04:17 2013 192.168.1.23: Body: Name: Prueba Mod ID: 3 (0x3) - Dip Switches Mac: 00 E0 62 20 B3 C2 IP: 192.168.1.23 Subnet: 255.255.255.0 Gateway: 192.168.1.1 Booter: 4.0.165 OS: 4.0.337 CPU Rev: 1.0.1 PWB/P
Mon Dec 30 14:04:17 2013 192.168.1.23: Sending HELO msg
Mon Dec 30 14:04:17 2013 192.168.1.23: State: 0x2 Received data: 220 16b.tpn.terra.com ESMTP
Mon Dec 30 14:04:17 2013 192.168.1.23: Received Greeting.
Mon Dec 30 14:04:17 2013 192.168.1.23: State: 0x2 Received data: 250 16b.tpn.terra.com
Mon Dec 30 14:04:17 2013 192.168.1.23: State: 0xA Received data: 334 XXXXXXXXXXXXXXXXX
Mon Dec 30 14:04:17 2013 192.168.1.23: Sending username.
Mon Dec 30 14:04:18 2013 192.168.1.23: State: 0xA Received data: 334 XXXXXXXXXXXXXXXXX
Mon Dec 30 14:04:18 2013 192.168.1.23: Sending password.
Mon Dec 30 14:04:18 2013 192.168.1.23:
State: 0xA Received data: 535 5.7.8 Error: authentication failed: another step is needed in authentication Mon Dec 30 14:04:18 2013 192.168.1.23:
Authentication Error.Obviusly server rejects password, but password is ok.
This is my email account.
Error 535??
My H0ECOM100 firmware

Image:
http://clip2net.com/s/6uQ68JI have other ECOM100 wich is running ok, sending mails from Gmail account.
What's is wrong?
LAST ADDED:
Error 535 5.7.8 Error: authentication failed: another step is needed in authentication
This error is caused by your SMTP server - it uses different type of authentication method.
By default plain method is used in our application.
But Use authentication is checked!!!!