I’ve been using Gmail for a long while now, and really like the web interface. In fact, I had *almost* completely stopped using a regular mail client for personal email. It was accessible anywhere, had an easy to use and understand layout, was fast, could collect email from several different accounts, now offers IMAP – the list goes on. BUT, I host most of my sites on Dreamhost, and for some reason Google has decided to Grey List them. Grey listing is a technique where a mail server is configured to ‘temporarily’ reject incoming mail from another mail server (or a range of them), with the knowledge that the standard configuration of those sending mail servers is to retry the attempt later on. When the sending server re-sends the mail, the grey listing server will accept it. The thinking is that spammers have their servers set to not retry because it draws attention to them and increases the risk that they will be identified as a spammer. There are some problems with this technique though, and they may be enough to make me stop using Gmail for good.

Instead of re-writing it, here’s what I posted on the Google groups problem solving list:

I understand why Google would try to use the technique, and technically it doesn’t violate the rules, since servers ’should’ try to resend it. BUT, they are not REQUIRED to resend it, so some email
*will* be lost. Also, it is mightily annoying when signing up on new sites where a confirmation email is sent immediately, and may have a 3 hour time-out but the email never reaches the user’s inbox until the next day – making it totally impossible to sign up on a new site! This puts email back into the dark ages in my opinion: we’re going from an instantaneous, useful tool to a clumsy, unreliable, and certainly unpredictable tool. Those kinds of tools are usually thrown away and replaced – so Google would be well advised to rethink this
decision.

UPDATE 12/7/07: It appears that Google has agreed to no longer grey list DH. Mail still doesn’t seem to be coming in very quickly from DH though it does eventually come through as far as I can tell.