Hard bounce count increasing for same list

[Anonymous]

Hi Community,

We set up an email campaign that is sending out 3 emails inviting people to an upcoming event. The first email send had 43 hard bounces and then the second email send had 19 bounces and the third email send had yet another 12 hard bounces.

We are sending the exact same list each time; we haven't added any new leads to the campaign.

So my confusion is: how did we get any more hard bounces after the first email? Shouldn't Marketo have automatically filtered out the hard bounces from the first email send, blocked them, and then have a bounce-free list moving forward for email send #2 and #3?

Thanks,

Hoi

[Josh_Hill13]

Hard bounces are not always fatal or occur every time. Suggest running a smart list

Bounced Email IS X on ZY dates

and looking and Email Bounced Reason and Email Suspended Reason to see if there are differences each time. Sometimes they are temporary blocks.

[Anonymous]

Thanks, Josh. I found some additional articles as well that has shed a lot of light into this.

For any other people curious, here are those articles:

Hard and Soft Bounces in Email - Marketo Docs - Product Docs

Maintaining a Directory of Leads Bouncing Emails

Thanks again,

Hoi