Email-to-fax.
Attach a PDF to an email, send it to <number>@fax.moarfax.com, and we'll fax it for you. No software, no app, no toner.
The address format
The local part of the email address (everything before the @) is the recipient fax number.
Use the full E.164 number — country code, area code, and subscriber number — with no spaces.
Dashes, dots, and a leading + are stripped before we parse the number.
The recipient must be a real US or Canadian fax number — 10 to 15 digits.
How it works
Five gates and a confirmation email.
SPF or DKIM must pass
We verify your sending domain via Mailgun's authentication checks. If neither SPF nor DKIM passes, the email is rejected to stop spoofing.
The recipient must look like a phone number
The local part of the address has to parse to a 10-15 digit E.164 number after stripping non-digits.
You must be a moarfax customer
We match the sender's email address against the email on your moarfax account. If your forwarder rewrites the envelope sender, we also check the From header.
There must be at least one attachment
PDF is preferred but Word, Excel, images, and 14 other formats are accepted. Multiple attachments are sent together as a single fax.
You need an active subscription with quota left
Email-to-fax counts toward the same monthly page bucket as faxes you send from the dashboard. If you're over quota, we reply with a clear "you've used X of Y pages" notice.
Confirmation email back to you
Once a fax is dispatched, we reply to the original email with the recipient, page count, fax ID, and a tracking link to your dashboard.
Securing your sending domain
moarfax requires SPF or DKIM to pass on every inbound email — that's how we know the sender is really you. For most people this is already done. The setup below covers the common cases.
📨 Gmail and Google Workspace
Personal Gmail accounts (@gmail.com) are already SPF and DKIM signed by Google. You don't need to do anything — just send from your Gmail address as normal.
Google Workspace accounts on a custom domain need two DNS records on the domain you send from. From your domain registrar (Cloudflare, Namecheap, GoDaddy, Route 53...) add:
Google's full guide: support.google.com/a/answer/33786
📨 Microsoft 365 and Outlook
Personal Outlook accounts (@outlook.com, @hotmail.com, @live.com) are already authenticated by Microsoft. No setup needed.
Microsoft 365 on your own domain needs:
Microsoft's DKIM guide: learn.microsoft.com → email-authentication-dkim-configure
🛠 Custom domain or self-hosted mail
If you run your own mail server (Postfix, Exim, Mailcow...), you need to publish at least one of SPF or DKIM. SPF is the easier of the two:
For DKIM, your mail server needs to sign outgoing messages. OpenDKIM is the standard companion to Postfix.
Once configured, publish the public key as a TXT record at {selector}._domainkey.yourdomain.com.
🛡 DMARC (recommended, not required)
moarfax does not require DMARC — SPF or DKIM passing is enough for us to accept your fax. But DMARC is the policy layer that tells other receivers (Gmail, Yahoo, Microsoft) what to do with mail from your domain that fails authentication. Publishing it protects your domain from being spoofed by anyone, including spammers using your name to send phishing.
Start with a "monitor only" policy to see who's sending as you, then ratchet to enforcement once you're confident:
After a couple of weeks of monitoring, change p=none to p=quarantine or p=reject to enforce.
dmarc.org/overview has the full picture.
How to verify it's working
-
Send yourself a test email from the address you use for moarfax. View its raw headers.
Look for
spf=passanddkim=passin theAuthentication-Resultsheader. - Use an external checker. mail-tester.com gives you a one-shot grade — send an email to the address it shows you, and you'll get a score along with SPF/DKIM/DMARC pass/fail.
- Send a real fax. Email a PDF to your fax number's email-to-fax address. Within a minute you should get a "fax dispatched" reply. If you get a rejection, the message will tell you exactly which gate failed.
Common problems
"Email failed both SPF and DKIM authentication" ▼
Your sending domain doesn't publish either authentication record, or both are misconfigured. Check your DNS with MXToolbox SPF lookup and the DKIM lookup tool for your selector. Most often the SPF record is missing the include for your provider.
"We couldn't find a moarfax account matching your email" ▼
We match on the exact email address you use to log in to moarfax. If you have an alias (like name+fax@yourdomain.com), it has to match the email on file exactly. Update your moarfax email in your profile if you want to send from a different address.
"Recipient is not a valid fax number" ▼
The local part of the address doesn't parse to a 10-15 digit phone number after stripping non-digits. Use 15551234567@fax.moarfax.com (with the country code), not 5551234567@fax.moarfax.com on its own.
"You've used X of Y pages this period" ▼
You're over your monthly page quota. Either wait for the period refresh date in the rejection email, or upgrade your plan to bump the limit immediately.
"No file attachments found" ▼
The email arrived without a file attached. Some email clients drop attachments when forwarding — attach the PDF directly to a new message rather than forwarding an email with the file.
Ready to fax from your inbox?
Subscribe, claim a fax number, and you can start sending email-to-fax in under a minute.