Compare · Gmail mail-merge tool · Updated July 2026

Autocloz vs GMass

GMass is a Gmail-based mass-email and mail-merge extension for sending campaigns from your inbox.

GMass is great for simple Gmail mail-merges, but it's tied to Gmail and is email-only with no CRM or other channels. Autocloz is a full platform: multichannel sequences, a free CRM, deliverability tooling and compliance — beyond what a Gmail extension can do.

Weighing your options? See the best GMass alternative.

CapabilityGMassAutocloz
ChannelsEmail (Gmail)Email, calling, LinkedIn, SMS & WhatsApp in one login
CRM / pipelineNoneFree-forever AI-native CRM
Deliverability + warmupBasicWarmup + DMARC/DKIM/SPF + placement tests
MailboxesYour Gmail50 free, unlimited on paid (Google/MS/SMTP)
Compliance gateNot a focusTCPA/DNC/quiet-hours across channels

Frequently asked

Is Autocloz a GMass alternative?

For anything beyond simple Gmail merges, yes. Autocloz adds multi-mailbox sending, warmup, deliverability monitoring, four more channels and a free CRM — not just a mail-merge from your inbox.

What is GMass best for?

Sending mail merges from inside Gmail with almost no setup. If your whole motion is occasional merges to a warm list from your own inbox, GMass is hard to beat on simplicity and price.

Where does it run out?

Volume and channels. GMass sends through your Gmail account, so you inherit Gmail's sending limits and reputation exposure. Autocloz rotates across many mailboxes with warmup and per-mailbox pacing, and adds calling, LinkedIn, SMS and WhatsApp plus a CRM.

Do I need to leave Gmail?

No. Connect your Google Workspace mailboxes to Autocloz and keep sending from the same addresses — the difference is pacing, rotation and the other four channels, not the address on the envelope.

More Autocloz comparisons

See why teams switch to Autocloz

All five channels + a free-forever CRM, unlimited users.