DKIM never switched on
Until you generate a key in the Admin console and start authentication, mail is signed with a Google-owned domain that doesn't align with yours, so DMARC fails.
Warm-up by provider
How to warm up a Google Workspace inbox
Short answerTo warm up a Google Workspace mailbox, turn on DKIM in the Admin console, publish SPF and DMARC, connect the mailbox over IMAP and SMTP with an app password, and ramp from 2-5 to 30-50 emails a day over two to four weeks. Google allows up to 2,000 messages a day per user, far above what cold email should use.
Step by step
Connect Google Workspace to RoxInbox
Connection method: IMAP/SMTP with an app password.
- 1
Turn on 2-Step Verification for the user; Google only offers app passwords when it's on.
- 2
Create an app password for RoxInbox in the Google Account security settings.
- 3
In RoxInbox, choose Add mailbox, then Google Workspace, and enter the address and app password.
- 4
RoxInbox checks SPF, DKIM and DMARC for the domain, then starts the ramp.
Sending limits 2026
Google Workspace sending limits
Google notes these limits can change without notice. They are ceilings for normal business email; cold-email mailboxes should stay around 30-50 a day.
| Limit | Value |
|---|---|
| Messages per user per day | 2,000 (rolling 24 hours); 500 on trial accounts |
| Total recipients per day | 10,000 |
| External recipients per day | 3,000 |
| Unique recipients per day | 3,000, of which up to 2,000 external (500 external on trial accounts) |
| Recipients per message via SMTP (IMAP users) | 100 |
Source: Google Workspace Admin Help: sending limits, checked 14 October 2026.
Ramp plan
A starting ramp for a new domain.
RoxInbox adapts this daily from real spam signals. Use the calculator for a plan for your own domain.
| Week | Emails per day | Note |
|---|---|---|
| Week 1 | 3-8 | Warm-up only |
| Week 2 | 8-18 | Check that DKIM signs with your own domain |
| Week 3 | 18-35 | Placement test at the end of the week |
| Week 4 | 35-50 | Start campaigns at a fraction of the plateau |
Pitfalls
What sends Google Workspace mail to spam
Warming on a trial account
Trial accounts are limited to 500 messages and 500 external recipients a day, and Google doesn't raise them during the trial.
Secondary domains without their own records
Each domain you send from needs its own SPF, DKIM key and DMARC record, even inside the same Workspace account.
FAQ
Google Workspace warm-up questions
How many emails can a Google Workspace account send per day?
Up to 2,000 messages per user in a rolling 24 hours, with 3,000 unique recipients of which 2,000 can be external. For cold email, stay around 30-50 a day per mailbox.
Do I need an app password for Google Workspace?
To connect over IMAP and SMTP, yes. Google offers app passwords only when 2-Step Verification is on for the user.
Why does DMARC fail even though DKIM passes?
If DKIM isn't enabled for your domain in the Admin console, Google signs with its own domain. That signature passes but doesn't align with your From domain, so DMARC fails.
Other providers: Outlook / Microsoft 365 · Yahoo Mail · Zoho Mail · iCloud Mail · Mail.ru · Yandex Mail · GMX / WEB.DE · Corporate SMTP
Warm up Google Workspace on autopilot.
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