Hi! I was wondering if anyone else was experiencing this. We have been getting a much lower than normal open rate the past two monthly sends. We used to average between 40-50% open rate but have now dropped to 29% for each send (august & september). I first thought it was our subject line but don't think that's the cause anymore. Our delivered emails remain the same so no drop in that.
I did research on the Gmail update that happened in July that penalizes larger lists and prioritizes engagement. We do have a lot of unengaged subscribers which I am thinking could be the cause of this. Would it be worth cleaning out these subscribers to see if this fixes the issue? Any other recommendations or think this may be something else?
#Marketing Cloud #Email Deliverbility
Good that rules out the most common silent failure cause, so this now points toward reputation/engagement rather than authentication. With 65k/123k on Gmail, you're well past the bulk sender threshold, so their spam-rate and engagement bar applies fully to you.
1. Gmail Postmaster Tools - do this first, it's the actual source of truth Everything above is inference from opens; Postmaster gives you Gmail's own view:
- Spam rate - this is the one that matters most. Gmail wants this under 0.10%, and anything approaching 0.3% risks bulk filtering. Marketing Cloud's own complaint tracking undercounts this people who just hit "report spam" without unsubscribing don't always show up the same way in MC's complaint metrics.
- Domain/IP reputation High/Medium/Low/Bad bucket, tracked daily
- Delivery errors and feedback loop data
- Needs domain verification (TXT record) if not already set up, this alone is worth doing regardless of the current issue, since you'll want the historical trend once you have it.
2. Segment your engagement report by ISP before doing anything else
If open rate dropped roughly evenly across Gmail/Yahoo/Outlook, that points more toward content/list fatigue than a Gmail specific inbox placement issue. If it's disproportionately Gmail, that confirms reputation/spam rate as the driver. This one check tells you which of the two paths below to prioritize.
3. On spam rate specifically check for a silent causeSince authentication passes, a spam rate creep is the next most likely explanation for exactly this symptom (delivered flat, opens down). Things that quietly push spam rate up:
- A list merge/import around July/Aug that added lower-quality or older contacts
- No visible/working one-click unsubscribe (Gmail requires the List Unsubscribe header AND that it actually works within 2 days) if someone can't easily unsubscribe, they hit "report spam" instead
- Content changes (new sender name, new link domains, more images) that shifted spam filter scoring independent of reputation
4. Sunset flow before mass suppression
Once you know the spam rate and whether it's Gmail specific, then move to hygiene but sequence it:
- Re-engagement send to 90+ day unengaged (low risk subject line ask if they still want these)
- Suppress non responders after that, rather than a single large deletion a sudden big cut can itself cause a short-term reputation dip right when you're trying to recover
