sashk:
> Hi,
>
> There are some destinations which refuse to talk to my server
> directly. My idea is to attempt deliver directly, and if it fails,
> attempt with fallback smtp server.
>
> Looking at documentation, it seems that smtp_fallback_relay might
> be useful, but reading about it suggests that it won't be helpful
> when there is 5xx errors.
>
> Here is an example of the error:
>
> relay=mxa-00018501.gslb.pphosted.com[208.86.201.80]:25, delay=50831,
> delays=50829/0.03/1.5/0, dsn=4.0.0, status=deferred (host
> mxa-00018501.gslb.pphosted.com[208.86.201.80] refused to talk to
> me: 554 Blocked - see https://ipcheck.proofpoint.com/?ip=xxx.xxx.xxx.xxx)
This was deferred, not returned to sender, therefore it may still be
delivered with smtp_fallback_relay.
Wietse
