TSS04 is an NDR for traffic shaping that indicates that mail originating from the network has been severely deprioritized. It's usually an escalation from a TS01 or TS02 that hasn't been resolved, but can but put in place without the lower tier traffic shaping deferrals if there are significant spikes or a particularly egregious spammer sending from your network. Contact Yahoo postmaster after getting rid of the sender on your network who is spamming or phishing.
On Wed, Nov 7, 2018 at 2:19 AM Mathieu Marnat via mailop <mailop@mailop.org> wrote: > Hi folks, > > > On some of our IPs we get a lot of 421 4.7.0 [TSS04] SMTP responses from > Yahoo. > > I cannot get a clear explanation from them and I see that this error code > is not listed in their official SMTP error code table. > > It seems to be a newly implemented error code and since they already had > error codes about complaints or unusual traffic what does this one could > mean ? More details would be helpful. > > > Regards, > > > Mathieu. > > _______________________________________________ > mailop mailing list > mailop@mailop.org > https://chilli.nosignal.org/cgi-bin/mailman/listinfo/mailop > -- Love is strong yet delicate. It can be broken. To truly love is to understand this. To be in love is to respect this. ~ Stephen Packer ~
_______________________________________________ mailop mailing list mailop@mailop.org https://chilli.nosignal.org/cgi-bin/mailman/listinfo/mailop
