One of Europe's largest payment processors can't send a valid email.
Viva.com sends verification emails missing the Message-ID header. Technically, RFC 5322 says it's a SHOULD, not a MUST. But Google Workspace and Zoho reject emails without it. So "technically optional" stopped mattering a while ago.
If your business runs on Google Workspace, you can't sign up for Viva.com's payment platform with your work email. The verification simply never arrives.
A one-line fix
The fix is trivial. Most email libraries add the Message-ID header automatically. This is the kind of thing that should never make it past basic testing.
When a customer reported the issue — complete with full logs and the exact RFC reference — support replied: "your account has a verified email, so there's no problem."
The real problem
Here's what's most concerning about that response. Unless you're actively monitoring bounce rates by receiving provider, you probably don't know this is happening. The customer reporting it might be your only signal that something is wrong.
And if support dismisses the report, you've just turned off the only alarm you had.
It raises a broader question worth asking of any business that depends on transactional email: how are you monitoring deliverability? Or are your customers doing it for you?
Credit to Ian Atha for the original writeup.
← All filings