First off, an introduction - just heard about Linode after the recent VPS reviews came up in the forums over at another VPS that I host with, and immediately came over to sign up.

I started by transferring my mail server (postfix+courier) over here, which I had up and running with no problems right up until I just recently decided to give postgrey a try.

Installed postgrey, configured it according to the debuntu howto, and off I went sending some test mails. None of them ever came back, and I saw no entries in my mail log similar to the ones suggested that I should be seeing.

After giving it some time, and no emails I decided to roll back and start over. I removed postgrey, and tried reverting my /etc/ back with etckeeper (which oddly enough did nothing to my /etc/postfix/main.cf file even though I rolled back to before the apt install).

After manually editing my main.cf to remove the postgrey settings in "smtpd_recipient_restrictions", and reloaded postfix, I'm still not getting any emails whatsoever. Made signing up for these forums a hotmail affair. So something in installing and removal of postgrey, I'm assuming, is still resident on the system.

Postgrey is gone, it's been removed and purged, no configuration files anywhere. The only edits I made to postfix to get it running was to my main.cf file, and I have reloaded it since. Yet still no emails.

I'd rather not have to purge postfix and reinstall, but I guess I will if I have to?

Disregard the above, I think I figured out that the original (-postgrey) problem was between keyboard and chair.

Since I fixed that I reinstalled postgrey on 10023 as suggested in the man page, and added the check relay to main.cf on the same port. Once again I haven't gotten any email since - my iptables is open on the loopback, so now I'm at a loss again as to why what should be a dead simple install keeps completely dropping my email...

What do your mail logs say? You should be seeing entries like

Dec  6 07:33:53 lixx-yy postgrey[2745]: action=pass, reason=triplet found, delay=306, client_name=mail.example.org, client_address=11.99.252.1, sender=bar@example.org, recipient=baz@fleem.example.com

Dec  6 07:39:40 lixx-yy postgrey[2745]: action=greylist, reason=new, client_name=unknown, client_address=7.201.4.16, sender=foo@example.net, recipient=baz@fleem.example.com

And when you start postgrey, something like this:

Dec  7 21:45:13 lixx-yy postgrey[2307]: Process Backgrounded
Dec  7 21:45:13 lixx-yy postgrey[2307]: 2009/12/07-21:45:13 postgrey (type Net::Server::Multiplex) starting! pid(2307)
Dec  7 21:45:13 lixx-yy postgrey[2307]: Binding to UNIX socket file /var/spool/postfix/postgrey/socket using SOCK_STREAM
Dec  7 21:45:13 lixx-yy postgrey[2307]: Setting gid to "102 102"
Dec  7 21:45:13 lixx-yy postgrey[2307]: Setting uid to "101"

My config is set up to use a unix socket as described here instead of listening on a port - that avoids any firewall issues.

Thanks Vance, I may take it off the port and use the socket as described, though I don't seem to be having any more troubles.

I would have posted back sooner but we got taken out of town unexpectedly; anyways it seems that under the worst of coincidences, my ISPs mail server was experiencing extremely heavy load the day I installed postgrey and the mail just never got delivered back to me for nearly 4-6 hours. So it wasn't postgrey, it was them! Alls well that ends well.