TL;DR
When you see "Google has blocked an outgoing email," one email was flagged, not your entire account. Stop re-sending the blocked message. Edit the email to remove spam-like wording, verify your SPF/DKIM records are valid, ensure your sender reputation is healthy, and re-send the revised email. If it delivers without errors, you're fixed.
Symptoms
Gmail or Google Workspace returns a bounce/error message: "Google has blocked an outgoing email"
lemlist shows a specific email step failed to send, even thoughthe campaign is running
Affected email contains promotional wording, suspicious links, or heavy formatting
Only one email is blocked, other messages are sent normally
Environment
Applies to:
Users sending cold email campaigns through lemlist using Google Workspace or Gmail accounts
Emails containing promotional language, heavy formatting, or attachments that trigger spam filters
Recipients with strict security settings or tight whitelists
Step-by-Step Fix
Pause and review the blocked email
Open the failed email in your campaign and read it critically. Look for overly promotional phrases, all-caps, aggressive calls-to-action, or suspicious links.
✅ Verify: Compare it to successful emails you've sent. If it reads like spam, that's your first clue.
Edit the content for clarity and deliverability
Rewrite the subject line and body using clear, professional language. Remove spam-triggering words (e.g., "free," "urgent," "limited time"), excess punctuation (!!!, ???), and heavy formatting. Keep it concise and personalize it.
✅ Verify: The revised email reads naturally and doesn't sound like a sales pitch.
Check your sender reputation and domain health
Go to your DNS provider and verify your domain's SPF and DKIM records are properly configured. Use Google Postmaster Tools to review your sender reputation and spam complaint rate.
✅ Verify: Both SPF and DKIM tests return "pass," and your Postmaster reputation is in the green or yellow range (not red).
Respect recipient security settings
Some recipients use strict filters that block emails from unrecognized senders. For important contacts, ask them to add your email address or domain to their whitelist. For large campaigns, avoid sending attachments or non-trusted links in your first outreach.
Send a test email and monitor
Re-send the revised email to yourself or a colleague first. Then relaunch the step in lemlist.
✅ Verify: The email sends successfully, and no new "Google has blocked an outgoing email" errors appear.
Adjust sending practices going forward
Keep your daily sending within reasonable limits (see How Many Emails Can I Send Daily?). Stagger sends using lemlist's scheduling tools. Warm up new domains gradually and always use a professional (non-free) email address.
Confirm It's Fixed
✓ Your revised email sends without being blocked
✓ Google Postmaster Tools show a healthy sender reputation (green or yellow)
✓ Recipients receive your emails normally, no bounce or block notices
✓ No repeated "Google has blocked an outgoing email" errors for other messages
Why It Happens / Prevent This
Google temporarily blocks outgoing emails to protect users from spam. Main triggers:
Poor sender reputation: History of spammy or suspicious activity results in blocks.
Recipient's high-security settings: Tight whitelists or restrictive filtering reject unknown senders.
Spam-like words or content: Promotional phrases, misleading subject lines, or suspicious links trigger Google's filters.
To prevent this:
Keep bounce and complaint rates low
Use clear, professional language—avoid spammy wording
Respect recipient preferences—no attachments on first contact
Maintain proper SPF/DKIM authentication and use a custom tracking domain
Spread out sends and stay within the recommended daily limits
Alternatives
Send from a different verified sender: If one address is repeatedly flagged, use another Google Workspace address with a clean reputation while you resolve issues.
Simplify your message: Convert HTML emails to plain text, sometimes a plain-text version bypasses filters.
Contact your email provider: If you suspect a system-wide block, reach out to Google Workspace support for additional insights.