status=deferred delivery temporarily suspended: host smtp-in.orange.fr refused to talk to me: 421

Hi

For a few days, without having changed anything in the configurations, on several servers with ispconfig3 I have received emails with the message: relay=none, delay=0.14, delays=0.12/0.01/0/0.01, dsn=4.0. 0, status=deferred (delivery temporarily suspended: host smtp-in.orange.fr refused to talk to me: 421 opmta1mti34nd1 smtp.orange.fr V5ANrI8BSNdJT Too many connections, please check your configuration. Too many connections, slow down. OFR005_104 [ 104])

This happens on all email sent to orange.fr or wanadoo.fr

I've been looking for and testing postfix configuration changes for several days with for example smtp_destination_concurrency_limit = 10
bsmtp_destination_concurrency_limit = 10
But it does not change anything

I wrote to [email protected] but still no response.
According to my research, this same problem has happened to many people going back a long way in the years and it seems that it is a problem with the orange mail servers or a limit that is too low but difficult to confirm.
This is why I tried to reduce the smtp_destination_concurrency_limit values to 1 or 10 but I don't have the impression that this is applied despite a postfix reload and restart. Or simply the modification is useless.

I also checked if the server IP was not blacklisted, it is negative.

Thanks
Sebastien

 

Okay, thanks for reply