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[Brad Roberts]

Well, it sounds like one of two issues:

1) you're mail client is sending directly to the mx hosts for 
puremagic.com mails (ie, mail1 or mail2) and never retrying to send. 
Neither is a good idea.

or

2) your mail transport agent is never retrying.

I suspect the former more than the latter, though that'd be highly 
unusual for a mail client to do.

Either way, the 'error' message there is fully descriptive.  You need to 
re-try the send later.  This is standard greylisting behavior which both 
mail servers for puremagic.com use.

On 2/27/14, 1:47 AM, Piotr Szturmaj wrote:
> On 2014-02-26 05:50, Brad Roberts wrote:
>> Later,
>> Brad
>
> Now I've received your email but it seems I can't reply :)
>
> Instead, I'm receiving mail delivery error:
>
>   The mail system
>
> <braddr at puremagic.com>: host mail2.puremagic.com[99.179.5.161] said: 451
> 4.7.1
>      Please try again later (TEMPFAIL) (in reply to RCPT TO command)