Workflow Transactional EmailWorkflow Transactional Email

Email deliverability

History says Success but the email is not in the inbox. That combination is almost always deliverability, and it is worth understanding who controls what.

Who is responsible for what

Your email does not go out through us. It goes out through your mailbox - your Microsoft 365 tenant, your Google Workspace account, or your SMTP provider.

Stage Who controls it What "Success" in History means
Rendering the email This app The layout rendered and the variables resolved
Handing it to your provider This app Your provider accepted the message. This is what Success means
Delivering to the recipient Your email provider Not visible to us
Inbox or spam folder The receiving server Not visible to us

A Success row means your provider took the message. Everything after that is between your provider and the recipient's, which is why a green row and an empty inbox are not a contradiction.

That also means deliverability is mostly in your hands - and that is good news, because it is fixable.

The three DNS records

If you send from [email protected], the receiving server asks three questions. Missing answers are the most common reason transactional mail lands in spam.

SPF - is this server allowed to send for this domain?

A TXT record on your domain listing who may send on your behalf:

v=spf1 include:_spf.google.com ~all

Use the include your provider documents - include:_spf.google.com for Google Workspace, include:spf.protection.outlook.com for Microsoft 365, or whatever your SMTP provider specifies.

DKIM - was the message tampered with?

A cryptographic signature proving the message really came from your domain and arrived unmodified. Your provider gives you the record to publish; both Google and Microsoft have a one-click setup in their admin console.

DMARC - what should happen if the checks fail?

A TXT record at _dmarc.yourdomain.com:

v=DMARC1; p=none; rua=mailto:[email protected]

Start with p=none, which monitors without affecting delivery. Once your reports are clean, tighten to p=quarantine and eventually p=reject.

DMARC has moved from optional to expected. Gmail and Yahoo now require it from bulk senders, and its absence increasingly counts against low-volume senders too.

Checking what you have

Any DNS lookup tool works, or from a terminal:

dig +short TXT yourdomain.com
dig +short TXT _dmarc.yourdomain.com

You are looking for a line starting v=spf1 on the first, and v=DMARC1 on the second.

Beyond DNS

Send from a domain you own. A free consumer address as the sender is heavily penalised. [email protected] beats [email protected] every time.

Match the From domain to the authenticated one. Sending as [email protected] through a mailbox authenticated for a different domain fails alignment even when SPF and DKIM technically pass.

Keep transactional email transactional. Order confirmations, shipping updates and account notices are expected. Marketing blasts from a transactional setup damage the reputation your order emails depend on.

Include real identifying details. A postal address and a clear sender name in your footer preset. Absent contact detail is a spam signal, and in many jurisdictions a legal requirement.

Warm up gradually. A brand-new domain suddenly sending hundreds of emails looks exactly like a compromised account. Volume should grow over days.

Watch your images-to-text ratio. An email that is one big image with almost no text is a classic spam pattern.

If mail is still not arriving

Work through it in this order - each step rules out a layer:

  1. Check History. If the row says Failed, this is not deliverability - open it for the provider's error.
  2. Send a test email from Email Senders to an address at a different provider than the failing one, so you are not fooled by a single receiver's filtering.
  3. Check the spam folder at the destination. If it is there, the message was delivered - it is a reputation problem, so work through the DNS records above.
  4. Check your provider's own logs. Microsoft 365 and Google Workspace both keep sent-mail and delivery logs showing what happened after they accepted it.
  5. Check the recipient side. Corporate mail servers routinely quarantine mail from unfamiliar domains without informing the sender.

Sending IP allowlisting

If you use an SMTP relay that restricts senders by IP, the app shows its outbound address on the SMTP server page so you can allowlist it. This applies only to SMTP - Microsoft 365 and Google connections send through the provider's own infrastructure.