Outlook / Microsoft 365 Sending Limits (and How to Send More)

Hitting Outlook / Microsoft 365 sending limits? Here is what they are and how to scale past them.

Outlook / Microsoft 365 limits

Microsoft 365 limits ~10,000 recipients/day and 30 messages/minute. Bulk marketing needs a dedicated sending platform.

How to send more

• Move to a dedicated sending domain and IP.
• Authenticate fully and warm up gradually.
• Segment and keep complaints low.

How Rainmail helps

Rainmail sends from your own domain on a dedicated, isolated IP with SPF, DKIM, DMARC, reverse-DNS and managed warm-up handled for you, a REST API, and an AI watching deliverability — and it welcomes senders SES, SendGrid and Mailchimp reject, from $8. Run the free checker or see plans.