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I have a rails in one of the slices at Slicehost. I've setup postfix (sendmail) to send emails from my rails app.

All emails to Google Apps domain (to company setup google hosted paid email id) are getting delivered properly (but to spam folder).

But all emails to,, .. are not getting delivered and this is the line from my /var/log/mail.log

Dec 21 17:33:56 staging postfix/smtp[32295]: 5EB4810545B: to=<>,[]:25, delay=1.6, delays=0.02/0.01/1.5/0, dsn=4.0.0, status=deferred (host[] refused to talk to me: 553 Mail from not allowed - 5.7.1 [BL21] Connections not accepted from IP addresses on Spamhaus PBL; see [550])

and this is what i got for gmail

Dec 21 17:29:17 staging postfix/smtp[32216]: 0FA3310545B: to=<>,[]:25, delay=0.59, delays=0.02/0.01/0.09/0.47, dsn=5.7.1, status=bounced (host[] said: 550-5.7.1 [] The IP you're using to send mail is not authorized 550-5.7.1 to send email directly to our servers. Please use the SMTP relay at 550-5.7.1 your service provider instead. Learn more at                          550 5.7.1 v49si11176750yhc.16 (in reply to end of DATA command))

Please help. I have very little knowledge about setting dns, servers and stuff.

share|improve this question
up vote 4 down vote accepted

Your ip address (of the slice) is blacklisted at SpamHaus.

That is why emails are not being accepted. I would ask slicehost to provide you with a new ip address.

HEre is a link to check blacklists:

Here is an article on how to get the ip removed from spamhaus but keep in mind the chances of being able to remove it are dificult. it is easier to get a new ip from your provider.

hope this helps.

share|improve this answer
what about Gmail then. Gmail error is a different one - what can i do about that... :( – Anand Dec 21 '10 at 18:04
it is most likely the same problem even with the slightly different error. – Luma Dec 21 '10 at 18:15
SliceHost may also offer a smarthost (relay) for you to use instead of sending mail directly. – gravyface Dec 21 '10 at 19:01
thanks a lot. i've removed it. what can i do to prevent my ip from getting listed again in spam blocklists ? – Anand Dec 23 '10 at 4:59
Make sure you are not spamming :), keep your server up to date, patched, good root password, no root logins (login as a user first and use sudo etc, make sure your mail server does not allow email being sent without things like authentication. – Luma Dec 23 '10 at 18:38

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