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 ...@gmail.com, ...@yahoo.com, .. @hotmail.com are not getting delivered and this is the line from my /var/log/mail.log
Dec 21 17:33:56 staging postfix/smtp: 5EB4810545B: to=<email@example.com>, relay=j.mx.mail.yahoo.com[184.108.40.206]:25, delay=1.6, delays=0.02/0.01/1.5/0, dsn=4.0.0, status=deferred (host j.mx.mail.yahoo.com[220.127.116.11] refused to talk to me: 553 Mail from 18.104.22.168 not allowed - 5.7.1 [BL21] Connections not accepted from IP addresses on Spamhaus PBL; see http://postmaster.yahoo.com/errors/550-bl21.html )
and this is what i got for gmail
Dec 21 17:29:17 staging postfix/smtp: 0FA3310545B: to=<firstname.lastname@example.org>, relay=gmail-smtp-in.l.google.com[22.214.171.124]:25, delay=0.59, delays=0.02/0.01/0.09/0.47, dsn=5.7.1, status=bounced (host gmail-smtp-in.l.google.com[126.96.36.199] said: 550-5.7.1 [188.8.131.52] 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 http://mail.google.com/support/bin/answer.py?answer=10336 v49si11176750yhc.16 (in reply to end of DATA command))
Please help. I have very little knowledge about setting dns, servers and stuff.