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Why some guests never see the invitation
The invitation was almost certainly delivered. What happens after delivery is decided inside the guest’s own company, and this page explains how to tell the two apart.
Updated 2 October 2026
Delivered and seen are two different things
When a guest says they never got the invitation, it is rarely because nothing was sent. In almost every case the message reached their company’s mail server, was accepted, was scanned, and was then filed somewhere the guest doesn’t look.
That decision happens inside the recipient’s organisation, after the message has already arrived, and no sending platform can see it or override it. Everything up to that point is ours to get right. Everything after it belongs to their IT department.
What your report actually says
Most platforms print Deliveredagainst nearly every recipient, which reads as proof the guest received it. It isn’t. GuestMark deliberately does not do this. Each recipient carries the strongest thing that was genuinely observed about their message, and nothing stronger.
On a healthy corporate list most recipients sit on No signal. That is normal, and it is not the same as a problem.
Why “No signal” and not “Delivered”
Because we can’t prove arrival. Handing a message to the sending network says nothing about whether a mailbox exists at the other end. We have watched that same confirmation fire for an address that was never real. Printing “Delivered” over that would be inventing a fact, and you would plan a guest list on it.
Only three pills prove the guest received it: Opened, Read and Responded. Only Bounced and Failed prove they didn’t. Everything else is an absence of information, and our reports are built to look like one.
The three reasons a guest doesn’t see it
1. The address is wrong
A mistyped domain, a stray space, or someone who has left the company. This shows as Bounced or Failed, with a reason attached. It is the only genuine delivery failure of the three, it is usually a handful of addresses on any list, and we correct and resend them as a matter of course.
2. It was filed into Junk, or held in quarantine
This is the common one. Microsoft 365 and the security products layered on top of it score every inbound message for how much it resembles bulk mail. An event invitation is bulk mail by definition: designed in HTML, sent to a list, with tracked links. Score above that company’s threshold and it lands in Junk, or in a quarantine the recipient may never check.
None of this reflects on the sender. We have seen a single company’s guests go quiet on a send while our authentication passed cleanly and comparable companies on the same list responded normally. The difference was that company’s own filtering policy, not the invitation. Fleet, dealer, banking and insurance groups run the strictest settings of all, because they are the ones targeted by invoice fraud.
The limit of what any sender can see
No email platform, ours or anyone’s, can see whether a delivered message landed in the Inbox or in Junk. That verdict is reached inside the recipient’s organisation and is never reported back to the sender.
So we can tell you a message was accepted, and we can tell you whether anyone engaged with it. We cannot tell you which folder it sits in. That is precisely why the fix has to come from the recipient’s IT department, and why the request further down this page matters more than anything we can change at our end.
3. It was read, but never recorded
Outlook blocks images by default. Open tracking works by loading one invisible image, so a guest who reads an invitation without switching images on is recorded as never having opened it. Your “no signal” list always contains people who have read every word.
Why open rates mislead in both directions at once
Large companies scan inbound mail in a sandbox before releasing it to staff. That scan loads the message in full, tracking image included, which registers as though a person opened it. So opens run high for machines and low for humans, simultaneously.
From our own events
Scanners don’t only open mail. They click. We have watched a corporate security product follow the links inside an invitation and submit a response on behalf of guests who never touched the email.
Declining now needs a deliberate slider gesture, designed so that scanners can’t complete it, and accepting means filling in and submitting the RSVP form. Every response a guest submits is stored with the IP address and browser that sent it. That is why a response from the RSVP page is the one figure on your report that takes a person. Responses our team records on a guest’s behalf, for example at the door, are recorded without those details.
These are the two patterns we can actually see in the delivery data, and each one is a machine rather than a guest:
Signature 1
Clicks outnumbering opens at a company. Nobody follows a link more often than they open the email. Link-scanning software does.
Signature 2
A response whose browser details look automated rather than like a person’s phone or computer. Every RSVP from the guest page is stored with the IP address and browser that sent it.
We treat opens as background texture, never as a headcount. Confirmed RSVPs are the number we plan catering, seating and badges from, because an RSVP takes a person.
What GuestMark does on every send
- Full sender authentication. Invitations are sent as GuestMark <invitation@guestmark.co.za> and digitally signed, so a receiving system can prove the message came from us and was not altered in transit. SPF, DKIM and DMARC all pass and align, independently verified by our email provider.
- Live text, not one big image. Our invitation template is built as real text and layout, so it reads correctly with images switched off and scores lower as bulk mail. An email designed mostly as artwork loses this, so we keep the key details in text.
- A View in browser link on every email. It opens the exact invitation that was sent, hosted on our own domain, so a guest who finds the message in Junk, or has images blocked, can still read it properly and RSVP.
- WhatsApp as a second channel. The same invitation and RSVP link can go by WhatsApp, which bypasses corporate mail filtering entirely and is typically the fastest way to reach anyone the email missed.
- Per-recipient delivery feedback. Bounces and failures are recorded against the individual guest, so an undelivered list can be corrected and resent rather than discovered after the event.
The one thing that fixes it properly
Inbox placement is decided inside the recipient’s organisation, so the fix has to come from there. A request from the host brand to a partner, dealer or member organisation’s IT department carries weight that a supplier request never will. Sent a fortnight ahead of the invitation, it removes the problem for that audience completely.
Forward the text below to the IT contact at each major recipient organisation.
We are expecting event invitations from our event platform and would like them
to reach staff inboxes rather than Junk or quarantine.
Sender address: invitation@guestmark.co.za
Envelope domain: eversrv.guestmark.co.za
Link domain: guestmark.co.za
Sending platform: Everlytic
Sending IP range: 102.219.93.0/24 (shared Everlytic range; only if a
sender rule is not possible)
In Microsoft 365, either a mail flow rule setting SCL to -1 for this sender, or a
Tenant Allow/Block List entry, will do it.
In Mimecast or Proofpoint, a permitted sender policy on the envelope domain above.
The domain is fully authenticated (SPF, DKIM and DMARC all pass and align) and
can be verified before allowing.Two things that help today
- Share the RSVP link on your own internal channels. Mail sent inside a company never passes an external filter, so an intranet post, a Teams message or a dealer WhatsApp group reaches everyone the invitation missed.
- Ask guests to check Junk and Other on the day of the send. On a corporate guest list this recovers more people than any technical measure, and it works immediately.
If a specific company is affected, tell us which one. We can show you exactly what was sent to each of their guests and what came back, which is what their IT department will ask for.