Soft Bounce Error Messages: Yahoo, AOL, and Verizon

[Ande_Kempf4]

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.

[SanfordWhiteman]

This should be in Products‌ (central peer support space).

[Ande_Kempf4]

This is in Products.

[Jay_Jiang]

If you don't have an organically gathered database, or if you're sending emails to data 2+ years old, you may have hit a spamtrap/honeypot operated by the email networks you are currently blocked by

[Jay_Jiang]

In addition, if enough people mark the unwanted email as spam, the same thing happens. That's why it's better, in terms of risk, to remove unengaged leads from your database than to keep sending them emails in hopes they finally engage.

[Ande_Kempf4 · Accepted solution]

Question Resolved

After discussing this issue with Courtney Grimes she explained that this is a pretty standard case of greylisting for Oath (AOL/Yahoo/Verizon). What happens is a person will hit the "HEY THIS IS SPAM " button, which then sends a feedback loop to Marketo to unsubscribe the person.

If enough people do that (and mind you, the threshold is comically low) then it'll trigger a response on Oath's side to say this sender is getting too many complaints.

To determine what audience is doing this you'll need to build a smart list of folks who unsubscribed without filling out an unsubscribe form. Use Data Value Changed and Reason = Customer complaint received from ISP". The list narrows down the audience causing the user complaint issue.

Hope this helps anyone else who runs into a similar problem!