GMass sends from Gmail. Gmail accounts are more fragile than dedicated infrastructure.
GMass makes Gmail sending fast and low-friction. You connect a Google Sheet, configure a campaign, and send from your inbox. That convenience is the point.
The fragility is also the point. A Gmail account used for outreach has lower bounce tolerance than a dedicated cold email domain. Google is quick to throttle or suspend accounts that produce high bounce rates or unusual sending patterns. The list that enters your Google Sheet needs to be clean before GMass touches it.
The Google Sheets import creates a specific risk window.
A Google Sheet that feeds a GMass campaign can contain any email address that was ever added to it — invalid addresses from old exports, role-based inboxes that were never filtered, catch-all domains that look clean but are not, stale contacts that have not been updated in months.
GMass will attempt to deliver to every row in that sheet. That means the quality of your sheet at the moment of campaign launch determines your bounce exposure for the entire send.
| Field | Why it matters before GMass sends |
|---|---|
| The address that GMass delivers to — must be verified before the sheet is finalized | |
| Domain | Catch-all detection, MX validity, company matching |
| Source | Apollo, LinkedIn export, scraped data, manual entry — each source has different decay rates |
| Duplicate rows | GMass does not automatically deduplicate — repeated addresses mean repeated sends |
| Previously bounced | Any address that bounced before should not re-enter a sheet without re-verification |
What happens when the wrong address enters a GMass campaign.
| Problem | What GMass sees | What Google sees |
|---|---|---|
| Invalid address | Bounce event | Sending account generated a bounce |
| Catch-all with no real mailbox | Delivery accepted, but no real recipient | Possible future complaint when the address routes nowhere useful |
| Role-based inbox with no reply path | Delivery accepted, open unlikely | Low engagement signal — affects inbox placement |
| Stale address now belonging to someone else | Delivery accepted, wrong person receives it | Complaint or spam report risk |
| Duplicate address | Multiple sends to same contact | Complaint risk from the recipient |