Valid subscribers bounce as "Suspended" even though their address is fine, and I never sent them a bad email
Constant Contact runs a network-wide suppression: an address that bounced as Non-existent from any Constant Contact customer's send gets a 15-day hold, and a second non-existent bounce moves it to an indefinite "Suspended" hold that silently blocks your campaigns. That is why correct, willing contacts (a spouse, a coworker) never receive your newsletter with no obvious cause on your end.
The fix
Check each blocked contact's bounce report for the Suspended category before assuming a content or spam problem. You can unsuspend a small batch yourself and use QuickSend to resend, but if an address re-bounces as Non-existent it goes straight back into suspension, so do not mass-unsuspend and re-blast: repeatedly hitting dead mailboxes damages your reputation. For a larger batch (Constant Contact points to roughly 10 to 15 or more at once), call the Constant Contact Deliverability team to run the unsuspension and investigate why a receiving server keeps returning those addresses as non-existent.
My open rate cratered from 45% to 10% overnight and I assumed we'd been spam-foldered
Open rates fall off a cliff with no change to content, list, or authentication, and senders conclude they are landing in spam, but the cause is usually measurement, not placement. Apple Mail Privacy Protection and bot prefetch inflate opens industry-wide, and Constant Contact's own open counting churned in early 2026, so reported opens dropped while inbox placement was unchanged.
The fix
Stop diagnosing inbox placement from open rate. Constant Contact launched bot and proxy open filtering in February 2026 (briefly excluding those opens and pushing rates down), pulled it back in March after feedback, and re-released it so the standard open rate still counts all opens with a separate confirmed open rate shown alongside. A swing that tracks one of these reporting changes is almost always measurement, not the spam folder. Judge deliverability from clicks, spam complaint rate, and an actual seed or inbox placement test, and define your engaged segment by recent clicks rather than opens.
We build our "most engaged" segment off open rate, and it's quietly full of people who never actually read us
Constant Contact's engagement segmenting historically leans on opens, but Apple Mail Privacy Protection pre-loads the tracking pixel on delivery, so Apple Mail users register as "opened" whether or not a human looked. Senders end up mailing an "engaged" segment padded with dead Apple contacts, which keeps complaint and non-response signals high and drags placement down.
The fix
Redefine your active segment around clicks in the last 60 to 90 days, not opens, and route open-only contacts into a re-engagement flow before your next broad send. Constant Contact's 2026 update now splits Confirmed Opens from Proxy Opens and calculates open rate on confirmed opens only, which makes your numbers more honest, but even a confirmed open is weaker proof of interest than a click. Clicks are the one signal Apple MPP cannot manufacture, since it pre-fetches images and pixels but never link clicks, so build the money segment on clicks.
We designed the whole newsletter as one big image in the drag-and-drop editor and it went straight to junk
Constant Contact's visual editor makes it easy to drop in a single designed graphic with almost no live text, and image-heavy mail with little text is a documented spam signal because filters cannot read text baked into an image. It is a risk multiplier, not a guaranteed trigger: modern Gmail, Yahoo, and Microsoft weigh sender and domain reputation far more than raw pixel ratio, so it compounds risk most when your reputation is already thin.
The fix
Do not rely on an image-only email. Put your real copy as live HTML text in the body and use images to support it. Constant Contact's own guidance is about 20 lines of text or less per image, plus a descriptive image description (alt text) on every image so the message still degrades gracefully when images are blocked. If you have a designed graphic, upload the plain version with the words left off and add the words as real text beside it.
Constant Contact froze the account after 14 spam complaints and demanded 3/4 of the list be deleted
A sender with six years of steady metrics sent to 6,800 contacts, got 14 spam complaints (about 0.2%), and had the account placed on hold until all contacts not engaged in the last 18 months were removed. Complaint rates that were tolerated before now breach the post-2024 Gmail and Yahoo threshold, and older-skewing audiences often hit "mark as spam" as if it were an unsubscribe button, pushing complaints over the limit on Constant Contact's shared IPs.
The fix
Keep spam complaints under 0.1%, since 0.2% is now high enough to get an account suspended and can indicate stale or tainted addresses. Stop mailing the disengaged tail: exclude anyone who has not opened in roughly the last six months, which both lowers complaints and removes dormant addresses that ISPs may have converted into spam traps. Make the unsubscribe link large and obvious so recipients who no longer want mail click it instead of reporting spam. Do not fight the list purge, because on a shared IP pool your bad addresses degrade deliverability for everyone on those IPs, which is why the provider enforces it.
