Is anyone else noticing a higher number of soft bounces lately?

[David_Edelson]

In the last week the number of soft bounces we've been seeing is jumping up quickly.  Is anyone else having this issue?

These bounces are for mailing lists that we send to at least once per week.  In one case a smart list of about 500 went from no soft bounces in the last month to about 10-25 for each of the last few messages we've sent.  On this list we have about 15 staff members.  In each of the last few sends, 3 or 4 staff members would bounce but the others would still get it.  This seems to be the same for other domains that have multiple receiving the message.  

Anyone have any ideas? 

[JessicaMeyers]

Have you looked into any of the bounce details for the records getting soft bounces? You would navigate to the bounce activity in the lead activity history and see what the cause is. I then find it helpful to see if there are trends (eg the same bounce details for a domain, or specific email). 

Example of bounce details are below. 

[David_Edelson]

Thanks for the reply, unfortunately when we check that all we get is "The email address is suspended until ..." And a date 24 hours in the future.

[Katja_Keesom · Accepted solution]

In that case you should also check out the Email Suspended Cause field for more information. The Email Suspended gets activated when your email is marked as spam. It is quite possible that some email activity in your own instance or another Marketo instance that is using the same email sending IP address has caused a temporary blacklisting via one of the tools out there. This generally does resolve itself within one or two days (unless you or the other IP address user is consistently sending out spammy emails).

There's several tools out there where you can check your IP address against most common blacklists.

More info on the Email Suspended field can be found here: https://nation.marketo.com/t5/Knowledgebase/How-the-Email-Suspended-field-works/ta-p/253972

[David_Edelson]

Thanks, that's very helpful--it looks like Microsoft/Outlook had marked the IP as being spam and we reached out to have it delisted. 

I still wonder though, how did the message soft bounce for 3 staff members but not the other 12 on the list, and that's the same for other organizations on the list?  For nearly every bounce, someone else at the same organization received, opened, and in many case clicked links the message. 

[Katja_Keesom]

Could it be that these individuals have whitelisted your sender account specifically?

[SanfordWhiteman · Accepted solution]

If the sender IP is rate-limited by the recipient, but not completely blocked, that's what you'd see: a portion of recipients (and not the same recipients each time, it's effectively random) receiving emails, the rest being soft-bounced for being over the limit.