Bulk Email Software

SIGN UP
LOGIN
SIGN UP
LOGIN

Send Beyond Office 365 Daily Limits

Microsoft Office 365 is an excellent platform for business communication, but it was never designed to be a high-volume outbound email service.

If your organization regularly sends newsletters, customer notifications, invoices, appointment reminders, marketing campaigns, political outreach, or large-scale transactional emails, you’ve probably encountered one of Microsoft’s outbound sending limits.

The most well-known is the 10,000 recipient limit per mailbox over a rolling 24-hour period. Once that limit is reached, Office 365 stops sending until enough time has passed for your rolling total to drop below the threshold. Microsoft also enforces limits on recipients per message and message submission rates to protect its infrastructure from spam and abuse.

For growing businesses, these limits can become a bottleneck.

That’s where Hotsol Managed SMTP comes in.

Why Office 365 Has Sending Limits

Microsoft’s email platform is optimized for business communication—not mass email delivery.

To maintain service quality and prevent spam, Exchange Online applies limits including:

  • Up to 10,000 recipients per mailbox every rolling 24 hours
  • Up to 1,000 recipients per individual message (administrator configurable)
  • Approximately 30 message submissions per minute

These restrictions are intentional and cannot simply be disabled. Microsoft even recommends using specialized third-party email providers for legitimate bulk email delivery.

The Problem

Imagine you need to send:

  • Product announcements
  • Customer invoices
  • Membership updates
  • Political fundraising emails
  • Legal notices
  • Event invitations
  • Marketing campaigns

Everything runs smoothly—until your mailbox reaches Microsoft’s limit.

Suddenly:

  • Emails begin failing.
  • Campaigns stall midway through.
  • Customer communications are delayed.
  • Sales opportunities are lost.
  • Automated systems stop sending.

For organizations that rely on email as a revenue channel, that’s unacceptable.

What is Hotsol Managed SMTP?

Hotsol Managed SMTP is a professionally managed outbound email infrastructure designed for organizations that need to send significantly more email than traditional business mailboxes allow.

Instead of relying solely on a Microsoft mailbox to deliver every message, your applications, CRM, marketing platform, or internal systems route outbound mail through Hotsol’s managed infrastructure.

The result is a scalable, monitored sending environment built specifically for high-volume outbound email.

Benefits of Hotsol Managed SMTP Send Beyond Office 365 Limits

Continue sending even after your Office 365 mailbox reaches Microsoft’s daily recipient limits. Your business doesn’t stop because a mailbox hit an arbitrary threshold.

Built for High-Volume Sending

Whether you’re sending:

  • Millions of marketing emails
  • Transactional notifications
  • Customer updates
  • Automated workflows

Hotsol Managed SMTP is designed for sustained outbound delivery.

Better Deliverability

Sending large volumes of email isn’t just about quantity.

Inbox placement matters.

Hotsol helps manage:

  • Sending reputation
  • IP health
  • Authentication
  • Bounce handling
  • Throttling
  • Infrastructure monitoring

The goal isn’t simply sending more email.

It’s getting more email delivered.

Protect Your Primary Office 365 Environment

Using your primary Microsoft mailbox for bulk email can impact its reputation.

Separating bulk mail from day-to-day employee communication helps keep business email flowing normally while marketing and automated traffic use dedicated infrastructure.

Managed Infrastructure

Running your own SMTP servers means managing:

  • Server security
  • Software updates
  • IP reputation
  • DNS records
  • Monitoring
  • Scaling
  • Authentication

Hotsol manages the infrastructure so your team can focus on growing the business—not maintaining mail servers.

Perfect For

Hotsol Managed SMTP is ideal for:

  • Marketing agencies
  • SaaS companies
  • Ecommerce stores
  • Healthcare providers
  • Political campaigns
  • Law firms
  • Insurance companies
  • Financial services
  • Educational institutions
  • Large enterprises
  • CRM platforms

••Marketing automation systems

Keep Your Applications Sending

Many business systems depend on SMTP:

  • CRM platforms
  • ERP software
  • Customer portals
  • Ecommerce platforms
  • Accounting software
  • Internal applications
  • Marketing automation
  • Custom software

When Office 365 throttles outbound mail, these systems can stop communicating with customers.

Hotsol keeps critical communications flowing.

Scale Without Rebuilding Your Email Strategy

Instead of purchasing additional Microsoft mailboxes or constantly rotating senders to stay under daily limits, organizations can centralize outbound delivery through a managed SMTP service designed for scale.

That means:

  • Fewer interruptions
  • Higher reliability
  • Better monitoring
  • Greater sending capacity
  • Simplified email operations

Is Hotsol Managed SMTP Right for You?

If your organization regularly sends thousands—or even millions—of legitimate emails, Microsoft Office 365 should remain your collaboration platform, while Hotsol Managed SMTP handles the heavy lifting of outbound delivery.

Whether you’re growing your customer base, expanding marketing efforts, or powering automated business communications, Hotsol provides the infrastructure needed to send at scale without running into Office 365’s built-in sending limits.

Ready to Send More?

Don’t let Microsoft throttling dictate your business communications.

With Hotsol Managed SMTP, you can expand your sending capacity, improve deliverability, and keep your email programs running smoothly—even after Office 365 reaches its daily limits.

Managed SMTP Plans for every business

Powerful, reliable email delivery infrastructure designed for high-volume sending needs. Built for companies that require more control, scalability, and performance than traditional email providers.

M-SMTP 1

$400

BILLED MONTHLY

  • 2 Sending Domains
    2 Mailboxes
  • 250K Emails Monthly
  • Daily Optimization
  • 24/7 Email & Chat Support
  • Domain Warm Up
  • Blacklist Monitoring
  • Feedback Loops
SELECT
MOST POPULAR

M-SMTP 2

$800

BILLED MONTHLY

  • 4 Sending Domains
  • 4 Mailboxes
  • 500K Emails Monthly
  • Daily Optimization
  • 24/7 Email & Chat Support
  • Domain Warm Up
  • Blacklist Monitoring
  • Feedback Loops
SELECT

M-SMTP 3

$1,200

BILLED MONTHLY

  • 8 Sending Domains
  • 8 Mailboxes
  • 1MM Emails Monthly
  • Daily Optimization
  • Phone & Priority Support
  • Domain Warm Up
  • Feedback Loops
  • IP Blacklist Monitoring
  • Deliverability Management
SELECT

M-SMTP 4

$1,500

BILLED MONTHLY

  • 12 Sending Domains
  • 12 Mailboxes
  • 1.5MM Emails Monthly
  • Daily Optimization
  • Phone & Priority Support
  • Domain Warm Up
  • Feedback Loops
  • IP Blacklist Monitoring
  • Deliverability Management
SELECT
Scroll to Top