How to authorize my SMTP ip

Question

when I send mail to gmail through SMTP I got a erro

550 5.7.1 http://mail.google.com/support/bin/answer.py?answer=10336

follow the link it said

'The IP you're using to send email is not authorized...'

In order to prevent spam, Gmail refuses mail when the sending IP address does not match the sending domain. To send mail from your server to Gmail, we suggest using the SMTP relay provided by your ISP. Please note that we are unable to whitelist IP addresses or otherwise make exceptions at this time.

It seams that, gmail will test my ip with MX record, (for this test, I send from localhost), but if myhost.com has 3 MX record, will google test each MX to match my ip, or is there any way to bind a domain to a ip, not bind an ip to a domain.

Update

After google, I think the most import thing is set DNS PTR.

Answer 1

I think the problem is that you are not using SSL, which is demanded by Google.

Answer 2

You should use the gmail smtp server as your outgoing mail server. Then Gmail will authorize and process your email.