What restrictions apply to sending bulk emails?

Valid for Mail Basic, Mail Business, Microsoft Exchange, and Google Workspace.

This article explains the restrictions that apply when sending bulk emails via the IONOS mail server.

When sending bulk emails via the IONOS mail server, limits apply to prevent abuse. Depending on your product, the following limits apply:

Mail Basic and Mail Business

The maximum number of emails you can send per hour depends on the following criteria:

The date on which the email account was created

AGE OF EMAIL ACCOUNT	MAIL BASIC AND MAIL BUSINESS
0–7 days	50 emails per hour
8–14 days	100 emails per hour
15–30 days	400 emails per hour
> 30 days	500 emails per hour

If this limit is exceeded, the following error message is displayed:

The message could not be sent. Error message from the mail transport server:
450 -
450-Requested mail action not taken: mailbox unavailable
450 Mail send limit exceeded.

Microsoft Exchange

Maximum number of emails per minute via IMAP or POP:

Contract duration	Microsoft Exchange
0–7 days	1 email per minute
8–14 days	2 emails per minute
15–30 days	7 emails per minute
> 30 days	10 emails per minute

Maximum number of recipients per day when sending via Outlook/Active Sync:

Contract duration	Microsoft Exchange
0–7 days	1,500 recipients per day
8–14 days	3,000 recipients per day
15–30 days	12,000 recipients per day
> 30 days	16,000 recipients per day

Maximum number of recipients per email sent:

Contract type	Number
Microsoft Exchange	500 including CC and BCC (contact/mailing lists are counted as 1 recipient)

Google Workspace

Limits	Number
Emails per day	2000
Automatic email forwarding	10,000
Email filters for automatic forwarding	20
Recipients per email	2000
Recipients per message via SMTP (POP/IMAP users) or the Gmail API	100
Recipients per day	10,000
External recipients per day	3,000
Unique recipients per day	3,000