Using the free plan
Zoho's free plan doesn't offer IMAP access, so external tools can't connect. Use a paid plan for any mailbox you warm or send from.
Warm-up by provider
How to warm up a Zoho Mail inbox
Short answerTo warm up a Zoho Mail mailbox on a paid plan, enable IMAP access, connect it over IMAP and SMTP, publish SPF, DKIM and DMARC, and ramp from 2-5 to 30-50 emails a day over two to four weeks. Zoho limits external sending per hour, from 50 to 500 depending on reputation, and doesn't allow bulk sending.
Step by step
Connect Zoho to RoxInbox
Connection method: IMAP/SMTP.
- 1
Make sure the mailbox is on a paid plan; Zoho's free plan doesn't include IMAP access.
- 2
Turn on IMAP access in Zoho Mail settings. If two-factor authentication is on, create an application-specific password.
- 3
In RoxInbox, choose Add mailbox, then Zoho, and enter the address and password.
- 4
RoxInbox checks the domain's DNS and starts the ramp.
Sending limits 2026
Zoho sending limits
Zoho's external limit moves with your reputation, so a new mailbox may sit at the low end. Aliases, delegated mailboxes and auto-replies count toward the quota.
| Limit | Value |
|---|---|
| External emails per hour | 50-500, set dynamically by sender reputation (rolling one-hour window) |
| Internal emails per hour | 1,000 |
| Recipients per message | 150 on paid accounts, 100 on free accounts (to, cc and bcc combined) |
| Bulk or burst sending | Not supported and not permitted under Zoho's business usage policy |
Source: Zoho Mail: limits and policies, 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 | Spread sends across the day to stay within hourly limits |
| Week 3 | 18-35 | Placement test at the end of the week |
| Week 4 | 35-50 | Start campaigns slowly |
Pitfalls
What sends Zoho mail to spam
Bursts
Zoho measures sending per rolling hour. Sending a whole day's volume at once is treated as burst sending, which its policy doesn't permit.
Forgetting DKIM
Zoho needs a DKIM key added in the admin console and published in DNS; it isn't on until you do.
FAQ
Zoho warm-up questions
What is Zoho Mail's daily sending limit?
Zoho publishes hourly limits instead: 50-500 external emails per hour depending on reputation, over a rolling one-hour window. Bulk sending isn't permitted.
Can I warm up a free Zoho Mail account?
Not with an external tool, because the free plan has no IMAP access. Use a paid plan.
Other providers: Outlook / Microsoft 365 · Google Workspace · Yahoo Mail · iCloud Mail · Mail.ru · Yandex Mail · GMX / WEB.DE · Corporate SMTP
Warm up Zoho on autopilot.
RoxInbox connects in five minutes, checks your DNS first, and shows placement at every provider.