Problems with Sending Mail / Greeting

I am getting the following error on an intermittent basis when sending to this county’s email servers. It will not work for a couple of days and then suddenly start working. It will be fine for a week or more then act up again. Any ideas what causes this error message and failure?

Hi. This is the qmail-send program at
I'm afraid I wasn't able to deliver your message to the following addresses.
This is a permanent error; I've given up. Sorry it didn't work out.

Connected to but greeting failed.
Remote host said: 554

The 554 error is a generally vague error, which can mean that their mailserver doesn’t like the way your message is being sent, and believes it to be spam.

The error “greeting failed” confuses me, as when I send the standard telnet greetings (essentially mimicking what your mailserver sends), the server accepts the gretting.

dlloyd@dlloyd-laptop:~$ telnet 25
Connected to
Escape character is ‘^]’.
mail from:
250 sender <>

You are welcome to open a support ticket with us and we can actually try to diagnose the problem in realtime.

In the meantime, I’d make sure that you have accurate reverse DNS records and make sure that your IP isn’t on any spam lists.

I have verified that I am not on any SPAM lists and that my reverse is correct (as far as I can tell). After going round and round with this all of a sudden it started working. Weird… then a couple of days/weeks later it started acting up. Spent some additional time talking with their techs. It would appear that they use SenderBase IronPort for their SPAM prevention (something that isn’t reported in the normal places). We keep bouncing in and out of their “bad” list and that was what was causing the problem. We still have no idea of why.

Hmmm… that’s really odd. It sounds like a problem on their end if it sometimes goes through and sometimes doesn’t. Are the headers the same on the good messages and the bad messages?
If anything, I’m guessing that this is not just affecting your server, and is likely on their end and they will want to fix it. Once again, you are encouraged to open a support ticket with details if and/or when this starts acting up again.