I'm trying to send text messages from the Tradestation message center, which requires the use of port 25.
In the from section, I used my gmail address, the relay.dynu.com for server, my dynu user name of Dkline55, dynu password and port 25. When I check no encryption, the error is "bad login or password". When I check SSL encryption, the error is "SSL handshake between client and server failed". Can you help??

The SMTP username should be the following:

relay@relay.davekline.com