[Mailman-Users] trying to understand Relay access denied (in reply to RCPT TO command)

Mark Sapiro mark at msapiro.net
Tue Oct 27 13:03:43 EDT 2015

On 10/24/2015 10:58 AM, Ricardo Kleemann wrote:
> Hi,
> I have some lists that have message delivery bounces returned and I can’t quite understand what’s going on.
> I’m using Postfix on the mailman server. In sending messages to either gmail or yahoo recipients, it seems to only work when the receiving end relays from a certain server, but errors when relaying through a different one. Not sure how to better explain so I’ll copy the examples here.
> The recipient addresses are people in Brazil, and the error cases are when mail is being relayed through there
> successful deliveries to yahoo and gmail, the relay shows a yahoo and gmail server respectively:
> Oct 23 13:18:07 localhost postfix/smtp[6101]: 0B0B344071: to=<xxxxxxx at yahoo.com>, relay=mta6.am0.yahoodns.net[]:25, delay=1.4, delays=0.01/0.19/0.15/1, dsn=2.0.0, status=sent (250 ok dirdel)
> Oct 23 13:18:07 localhost postfix/smtp[6077]: 08E0F44070: to=<xxxxx at gmail.com>, relay=gmail-smtp-in.l.google.com[]:25, delay=1, delays=0.01/0.61/0.05/0.33, dsn=2.0.0, status=sent (250 2.0.0 OK 1445631542 dl5si20130969pbb.108 - gsmtp)
> Bad delivery attempts to same recipients at yahoo and gmail, but this time it’s relaying through a server in Brazil:
> Oct 24 06:27:26 localhost postfix/smtp[11544]: B7064449E0: to=< xxxxxxx at yahoo.com>, relay=mx2.ibest.com.br[]:25, conn_use=17, delay=501, delays=0.03/501/0.2/0.21, dsn=5.7.1, status=bounced (host mx2.ibest.com.br[] said: 554 5.7.1 < xxxxxxx at yahoo.com>: Relay access denied (in reply to RCPT TO command))
> Oct 23 13:26:45 localhost postfix/smtp[8446]: 2039444A28: to=<xxxxx at gmail.com>, relay=mx2.ibest.com.br[]:25, conn_use=9, delay=498, delays=0.01/497/0.25/0.21, dsn=5.7.1, status=bounced (host mx2.ibest.com.br[] said: 554 5.7.1 <xxxxx at gmail.com>: Relay access denied (in reply to RCPT TO command)
> In all failure scenarios, the relaying server (for both yahoo and gmail recipients) was the same. But what exactly is the relay error? Is it complaining that my own server isn’t properly configured for relay, or is it a problem on mx2.ibest.com.br <http://mx2.ibest.com.br/>?

The MTA at mx2.ibest.com.br is saying it cannot relay mail from you to
yahoo.com and gmail.com.

Your postfix should always be relaying via one of the MX servers for
yahoo.com or gmail.com. I.e.

> $ dig mx yahoo.com
> ...
> yahoo.com. 1800 IN MX 1 mta6.am0.yahoodns.net.
> yahoo.com. 1800 IN MX 1 mta7.am0.yahoodns.net.
> yahoo.com. 1800 IN MX 1 mta5.am0.yahoodns.net.
> ...
> $ dig mx gmail.com
> ...
> gmail.com. 197 IN MX 10 alt1.gmail-smtp-in.l.google.com.
> gmail.com. 197 IN MX 30 alt3.gmail-smtp-in.l.google.com.
> gmail.com. 197 IN MX 40 alt4.gmail-smtp-in.l.google.com.
> gmail.com. 197 IN MX 20 alt2.gmail-smtp-in.l.google.com.
> gmail.com. 197 IN MX 5 gmail-smtp-in.l.google.com.

Possibly your Postfix configuration has some sender dependent transport
mapping that specifies mx2.ibest.com.br as the relay for some mail or
maybe your DNS is being corrupted somehow.

Mark Sapiro <mark at msapiro.net>        The highway is for gamblers,
San Francisco Bay Area, California    better use your sense - B. Dylan

More information about the Mailman-Users mailing list