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.
Best Answer
This happens when your IP address is listed in the Spamhaus PBL. This DNSBL contains a list of known dialup/dynamic IP address ranges which should not ordinarily be sending mail via SMTP.
To fix the problem, change your mail client's outgoing mail server settings to connect to port 587 instead of port 25.