How to Fix Canon imageRUNNER E351-0001 Send Error via SMTP and SMTPS
Joe B.
Reviewed for technical accuracy
Specialities: Canon imageRUNNER, Scan to Email, SMTP/SMTPS, Microsoft 365, Gmail/Google Workspace
Canon imageRUNNER E351-0001 send error — SMTP/SMTPS, TLS/SSL, ports & authentication troubleshooting
Technician
First I need a bit of context so we choose the right fix: which imageRUNNER / imageRUNNER ADVANCE / DX model is this, what mail service you’re using (Microsoft 365 / Office 365, Gmail / Google Workspace, on-prem Exchange, cPanel/ISP), and do you see this on all destinations or only some (scan to email, I-Fax, alerts)?
Technician
Common triggers for E351-0001 SMTP send error:
• wrong SMTP server name or DNS issue;
• incorrect port (25/465/587), SSL/TLS / STARTTLS mismatch;
• invalid or missing SMTP AUTH username/password;
• recent changes in Microsoft 365 / Gmail security policies (Basic auth disabled, OAuth/App Password required);
• firewall blocking outbound SMTP/SMTPS from the imageRUNNER;
• certificate or hostname mismatch for SMTPS.
Let’s run through a structured checklist so we clear E351-0001 and restore scan-to-email reliably — without guessing.
Technician
On the device’s Remote UI / web interface:
1) Open Settings/Registration → Function Settings → Send → E-Mail/I-Fax Settings (labels vary by model).
2) Under SMTP Server, confirm the exact hostname from your provider (e.g.
smtp.office365.com, smtp.gmail.com, your mail server FQDN). A typo or using an IP instead of FQDN is a classic cause of E351-0001.3) Check the port & encryption:
• For Microsoft 365 authenticated submit: 587 + STARTTLS (TLS).
• For SMTPS: usually 465 + SSL/TLS if your provider documents it.
• Port 25 is mostly for internal relay and often blocked externally.
4) Ensure Device E-mail Address is set and matches the sending policy if your provider requires a valid “From” domain.
If any of these are wrong or blank, the imageRUNNER will fail SMTP handshake and throw E351-0001 send error SMTP.
Technician
• Use a licensed mailbox or dedicated service account for SMTP AUTH, not a shared mailbox alone (unless configured correctly).
• In the Microsoft 365 admin center, SMTP AUTH for that account must be allowed if your org disabled legacy auth.
• On the Canon, set:
– SMTP server:
smtp.office365.com– Port: 587
– Encryption: STARTTLS / TLS
– Authentication: ON, with full UPN (e.g. user@yourdomain.com) and the correct password.
• Make sure the From address on the imageRUNNER matches the authenticated account or is allowed as a delegate sender.
If any of these are off, the MFP’s connection test fails and is reported as E351-0001 send error SMTP even though the network is fine.
Technician
For Gmail or Google Workspace:
• Server:
smtp.gmail.com• Port: 587 (TLS/STARTTLS) or 465 (SSL/TLS) if documented.
• Auth: full email address + App Password (if 2FA) or allowed SMTP credentials — “less secure apps” are no longer supported.
For ISPs / cPanel / hosting SMTP:
• Use the exact hostname, port, and encryption from their docs.
• Confirm the device IP is allowed to relay (some providers block unknown IPs → results in send error E351-0001).
Each mismatch — wrong encryption, blocked relay, disabled basic auth — looks to the Canon like a generic SMTP/SMTPS send error, so we tune each value to the provider’s current policy.
Technician
• Make sure the SMTP server name on the Canon matches the certificate CN/SAN (e.g.
smtp.office365.com, not a raw IP).• Verify the device has correct date/time and DNS servers; bad time or DNS causes TLS validation errors.
• If your mail server uses a self-signed or internal certificate, enable the appropriate trust options or use a hostname with a valid public CA cert.
• Avoid forcing SSL/TLS on port 25 unless your provider explicitly requires it; most secure submissions use 587 with STARTTLS or 465 with SSL/TLS.
Incorrect TLS mode or hostname mismatch = E351-0001 send error SMTPS even when username/password are correct.
Technician
• Your firewall blocks outbound TCP 587/465/25 from the printer’s IP. Allow the correct port to the SMTP host.
• Using Microsoft 365 relay: your public IP or connector isn’t authorized, so the connection or submission is rejected.
• Multiple DNS servers / captive portals: the imageRUNNER can’t resolve the SMTP FQDN consistently.
• Wrong “From” domain vs. SPF/relay rules causing hard rejections on submission.
Quick test: from a PC on the same VLAN, use
ping and telnet smtp-server 587 (or equivalent) to confirm reachability. If the PC works but the MFP doesn’t, we adjust firewall rules so the device can reach the SMTP host cleanly.
Technician
1) Confirm correct SMTP server FQDN, port (587/465/25), and TLS/SSL settings per your provider.
2) Set a valid device email address and enable SMTP authentication with the right account (M365, Gmail, etc.).
3) Ensure DNS, date/time, and certificate/hostname all align; avoid IP instead of FQDN.
4) Open outbound ports on the firewall; configure relays/connectors so the printer is allowed to send.
5) Run the device’s SMTP Connection Test. If it still fails, grab the detailed status and we map it to an exact fix in chat instead of trial-and-error.
This closes most E351-0001 cases in one pass and gets scan-to-email reliable again.
Technician
Quick answer: the accepted fix
Accepted approach for a Canon imageRUNNER E351-0001 SMTP/SMTPS send error: use the correct SMTP server FQDN, matching port (587/465/25) and TLS/SSL mode, enable SMTP AUTH with a valid mailbox, set a proper device email address, and allow outbound SMTP traffic. If the SMTP test passes and E351-0001 stops, scan-to-email is fixed; if not, adjust provider policies or firewall rules with expert help.
What Canon E351-0001 send error means on imageRUNNER devices
When a Canon imageRUNNER reports E351-0001 sending email, it usually indicates the device could not complete an SMTP/SMTPS session to the configured mail server. This can be due to an unreachable SMTP host, incorrect encryption (TLS vs SSL), blocked ports, invalid login, or stricter Microsoft 365 / Google Workspace policies. Treat it as a configuration and connectivity issue, not a random glitch.
How to verify your Canon SMTP/SMTPS fix worked
After adjusting your mail settings, confirm that:
- The device’s built-in SMTP Connection Test shows success, not E351-0001.
- Scan-to-email jobs arrive in target mailboxes without delay or bouncebacks.
- The From address and domain match your provider’s policies.
- No new send error / SMTP AUTH / TLS warnings appear in the device status logs.
If messages vanish or bounce, check headers: they’ll reveal whether SMTP AUTH, SPF/relay rules, or encryption still need tuning.
Canon SMTP send errors — quick pro tips
Most E351-0001 send error SMTP/SMTPS issues are fixed with precise, policy-compliant settings.
• Always copy SMTP settings from your provider’s latest documentation, not from old screenshots.
• For Microsoft 365, decide between authenticated submit on 587 or relay via connector — configure the imageRUNNER accordingly.
• For Gmail/Workspace, use App Passwords or service accounts where required; don’t rely on deprecated “less secure apps”.
• Lock down a dedicated scan account with limited rights so you stay secure and compliant while keeping scan-to-email stable.
Disclaimer: This guide is informational and does not replace your provider’s official documentation. Incorrect SMTP/SMTPS configuration can expose your domain to abuse or cause mail delivery failures. If unsure, work with a qualified expert.
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FAQ
What is Canon imageRUNNER E351-0001 send error?
E351-0001 is typically a send error indicating the device could not complete an SMTP/SMTPS connection — wrong server, blocked port, TLS failure, or SMTP AUTH problem during scan-to-email or I-Fax send.
Which SMTP ports and encryption should I use?
Most providers use 587 with STARTTLS (TLS) for authenticated SMTP. Some support 465 with SSL/TLS. Only use the port/encryption combination documented for your provider to avoid E351-0001.
How do I fix E351-0001 with Microsoft 365 or Office 365?
Use smtp.office365.com on port 587 with TLS, enable SMTP AUTH for the sending account, use valid credentials, and configure either authenticated submit or a proper relay connector that matches your IP and domain.
How do I fix E351-0001 with Gmail or Google Workspace?
Use smtp.gmail.com with TLS on 587 or SSL/TLS on 465 per policy, authenticate with a permitted account (often via App Password), and ensure the device’s From address and domain comply with Google’s requirements.
| Symptom | Likely cause | Quick action |
|---|---|---|
| E351-0001 on every send | Wrong SMTP server, port, or TLS mode | Match provider docs; use correct FQDN, port 587/465, and TLS/SSL setting |
| E351-0001 after password change | Invalid SMTP AUTH credentials | Update username/password or App Password on the imageRUNNER |
| E351-0001 only with Microsoft 365 | SMTP AUTH disabled or connector not configured | Enable SMTP AUTH for the account or configure relay connector properly |
| E351-0001 intermittent | Firewall or DNS issues, unstable route | Allow outbound SMTP ports; fix DNS; test connectivity from same subnet |
Step-by-step recap (Canon E351-0001 SMTP/SMTPS)
- Confirm the exact SMTP server name, port, and encryption from your mail provider.
- Set a valid device email address and enable SMTP authentication with correct credentials.
- Verify DNS, date/time, and hostname so TLS certificates validate properly.
- Allow outbound SMTP/SMTPS ports (587/465/25 as required) on your firewall.
- Run the SMTP connection test. If it fails, adjust according to the specific error or get live help.
Note for mixed and secure environments
- Align printer SMTP settings with your organization’s security (MFA, OAuth2, conditional access).
- Use dedicated, locked-down service accounts or relay connectors to keep scan-to-email compliant.
Sources
- Microsoft Learn — Configure printers and apps to send email with Microsoft 365/Office 365
- Google Workspace Admin Help — Send email from a printer, scanner, or app
- Canon Online Manual — List of error codes without messages (SMTP communication issues)
Filed under: Printers
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