Bounces and complaints are what get Gmail accounts restricted. These tools keep the list clean before, during and after a campaign.

Ways to add recipients

"To" field: paste addresses directly, as in any email.
Google Sheet: MailBrother options → GSheets Integration; columns become {Tags}.
Paste addresses / CSV: paste a list or upload a CSV/TSV with a header row. The email column is detected automatically; other columns become tags. Duplicates are removed and invalid lines skipped before anything reaches the "To" field.

Verify addresses

MailBrother options → Verify addresses checks everyone in "To": syntax, disposable domains, role addresses (info@, sales@), whether the domain has a mail server, and whether the address bounced in any MailBrother campaign in the last six months. Invalid addresses can be removed from "To" with one click; results are cached for 30 days. This does not contact the mail server, so a small share of dead mailboxes can still bounce.

Suppression list

Every unsubscribe, bounce and "stop" reply is added to your personal suppression list, and every new campaign skips those addresses automatically. On the Campaigns tab you can add addresses by hand, add a whole domain as @competitor.com, import a list from another tool (CSV) and export yours.

Before you send

The pre-flight check warns when recipients already got an email from you in the last 7 days, when a name column holds something that is not a name ("Hi ООО Ромашка"), when tags are empty in the first rows, when links go through shorteners, and when the subject or body looks like spam.

During and after

Auto-pause: if more than 8% of the first 30+ emails bounce, or three recipients in a row ask to stop, the campaign pauses and you get an email.
Write results back to the sheet: tick it in the send dialog and the source Google Sheet gets MB_Status, MB_Sent, MB_Opened, MB_Clicked columns that stay updated. Filter on MB_Status = Bounced to clean the sheet.
Copy addresses on the campaign page copies the addresses of any filter (opened, clicked, no reply…) for a new email.
Resend to unopened sends the same email again to everyone who never opened it.

Sending safely

Default interval between emails is 30 seconds; 30–60 seconds looks like a person.
New sending accounts are warmed up automatically: 50 → 100 → 200 → full limit over two weeks.
Tracking is off by default for 20 recipients or fewer, so personal notes carry no pixel and no rewritten links.
Every campaign email carries List-Unsubscribe headers, so Gmail shows its own Unsubscribe button.
After Send Mass you have 60 seconds to cancel.