AnsweredAssumed Answered

Soft Bounce Error Messages: Yahoo, AOL, and Verizon

Question asked by Ande Kempf Expert on Sep 17, 2019
Latest reply on Sep 18, 2019 by Ande Kempf

Question on Soft Bounces

 

Context/background: Recently warmed dedicated IP. This process went very well. After warming we sent a promotional email and the deliverability is terrible (around 60%). Note: about 8 days between last warming email send and first promo email.

 

Problem: Majority of bounces are soft and have returned error messages for Yahoo, AOL and Verizon. The error message returned are all:

554 5.4.5 [internal] (last transfail: 421 4.7.0 [TSS04] Messages from 192.28.155.34 temporarily deferred due to user complaints - 4.16.55.1; see https://help.yahoo.com/kb/postmaster/SLN3434.html)

Other information: IP Sender Score/Reputation all looks great. IP is not listed on any blacklists (According to ReturnPath. MXtoolbox and Talos)

 

Question: How do you mitigate this type of soft bounce error? It seems to be the one issue we're facing.

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