Operating mail servers? Perfer: Postfix and DKIM

Anyone here operating a mail server?  Preferably Postfix. Have you implemented DKIM?  Seems AOL refuses to talk to my mail server; most likely because I am not signing outgoing emails.  I thought I would try setting up DKIM to see if it will resolve the issue.

I find this interesting because just about all the websites I set up, the client wants emails from their domains.  Which generally means setting up a mail server.  Yes, I guess one could go with hosted mail but they probably won't like the idea of having to pay an extra $XX.XX a month for their email service ON TOP of the costs they are paying for the server/hosting.  For example, GoDaddy wants $3.99/month for five email addresses (2GB storage).

Perhaps Zarconia will be kind enough to offer some guidance.

Do you have proper reverse DNS entry for your server?

And do you have a DNS SPF record setup?

That is all i have ever done.

Mail servers will refuse mail from a mail server if it cannot do a reverse lookup. Also is a sender policy framework id is not setup (SPF Record) which identifies the mail servers that are allowed to send mail for your domain, then many other servers will refuse it.

Here is an interesting read on AOL.

http://www.dmsiusa.com/articles/aol-email-blocking.pdf

I thought I had but let me do some checks; maybe I overlooked some things when I was having issues setting this thing up.  If you recall my earlier post I simply threw my hands up in the air and redid the whole thing.

Note about sending emails to AOL

Special note about AOL:
It appears that AOL has recently restricted this even further:
They also require that reverse DNS points to a "fully qualified domain name" (we assume they mean a name with 3 or more segments, such as "mail.jhsoft.com"), and that this name does not contain the segments "in-addr.arpa" and is not just an IP address.
If you want to be able to send e-mail to AOL users, the reverse DNS record for your e-mail server IP address must adhere to this as well.
For details, please see http://postmaster.aol.com/Postmaster.Errors.php#whatisrdns

Thanks Deano, a check revealed that we don't have a rDNS entry.  I sent that on to the person handling the Domain name to get sorted.

Reverse DNS will likely need to be setup by your host/ISP, since the record is separate from your normal DNS records for the domain.  If the IP address is the same one used by your hostname, it should probably use that (e.g., server1.example.com resolves to 1.2.3.4, 1.2.3.4 resolves to server1.example.com).

I am running Postfix and use DKIM for outgoing mails. But even if you set it up on your server and get it working correctly, you will run into problems with dolphin. There seems to be a problem within dolphins phpmailer that needs to be set properly or otherwise the servers won't recognize it as signed correctly.

http://www.boonex.com/forums/topic/Outgoing-Mail-Signing-with-DKIM-Need-Help-.htm