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Send us your question and we will get back to you within 5 business days.
satbirsingh.dev@gmail.comGitHub Issues
Found a bug or have a feature request? Open an issue on GitHub.
Open an IssueFrequently Asked Questions
Why is my Gmail saying "This app isn't verified"?
This is a Google warning shown for apps that have not yet completed Google's OAuth verification process. The app is safe to use — click "Advanced" then "Go to Mass Email PRO (unsafe)" to proceed. This warning will disappear once the app is verified by Google.
I'm getting an SMTP authentication error. What do I do?
For Gmail SMTP, you must use an App Password, not your regular Gmail password. Go to your Google Account App Passwords, generate a new one, and paste it into the Password field. Make sure 2-Step Verification is enabled on your Google account first.
Is my contact data uploaded to your servers?
No. Your Excel or CSV file is parsed entirely in your browser using JavaScript. The contact data never leaves your device and is never stored on our servers. Only individual email payloads are sent to your SMTP server or the Gmail API at the moment you click Send.
What SMTP settings do I use for Outlook / Office 365?
Use the Outlook preset button in the SMTP configuration panel, or enter manually: Server:
smtp.office365.com, Port: 587, Encryption: TLS. Use your full Outlook email address and account password (or App Password if MFA is enabled).
How do I use dynamic variables like {Name} in my email?
After uploading your contact list, column names from your spreadsheet appear as clickable chips below the subject and body fields. Click any chip to insert it as a variable (e.g.,
{Name}, {Company}). When sending, each recipient's row values are automatically substituted.
My emails are going to spam. How do I fix this?
Email deliverability depends on your domain reputation, not this tool. Common fixes: (1) Use a custom domain email instead of a free Gmail/Yahoo address. (2) Set up SPF, DKIM, and DMARC DNS records for your domain. (3) Increase the delay between emails (3-10 seconds). (4) Warm up a new sending domain by starting with small batches.
Can I send attachments to specific recipients only?
Yes. Add a column to your spreadsheet (e.g.,
Attachment) and fill in file paths or filenames for each row. In Step 2, select that column as the Attachment Column. You can also upload files directly in Cloud Mode and reference them by filename.
How do I revoke Mass Email PRO's access to my Google Account?
Visit myaccount.google.com/permissions, find Mass Email PRO in the list of connected apps, and click "Remove Access". You can also click the "Disconnect" button within the app to end your current session immediately.