The QuickBooks Delivery Server Down error typically occurs when QuickBooks Online cannot connect to the email server to send invoices, sales forms, or other important documents . This error can be triggered by incorrect email address formats, special characters in invoices, misconfigured browser settings, or issues with attachments .

In this comprehensive guide, we'll cover what the Delivery Server Down error means, why it happens, and step-by-step solutions to resolve it quickly.

What Is QuickBooks Delivery Server Down Error?

QuickBooks Delivery Server Down error occurs when QuickBooks Online cannot connect to the email server to send invoices, sales forms, or other documents to customers . This error usually appears with messages like "Delivery Server Down" or "Unable to send your email" .

The error typically happens when:

You try to email an invoice or sales form as an attachment
The email bounces back from the recipient's email service
QuickBooks Online cannot establish a connection with the email server

Top Reasons for QuickBooks Delivery Server Down Error
Understanding the root cause is the first step to finding the right solution.

Here are the most common reasons this error occurs:

• Incorrect Email Address Format – The company email or customer-facing email contains prefixes like "email:" or is formatted incorrectly .
• Special Characters in Invoices – Using invalid characters (! @ # $ % ^ & * ( ) _ – = + : ") in invoice fields like description, attachment name, message, or custom templates .
• Location Email Address Issues – When using location tracking, the location's email address may be incorrect .
• Attachment Issues – Attachments exceeding 25 MB, being ZIP files, or containing special characters in filenames .
• Browser PDF Settings – Incorrect browser configuration for handling PDF files .
• Misconfigured Adobe Acrobat/Reader – Incorrect print settings in Adobe Acrobat or Reader .
• Internet Connectivity Problems – Unstable internet connection or network issues blocking the server connection.
• Firewall or Antivirus Blocking – Security software blocking QuickBooks from accessing email servers .

How to Fix QuickBooks Delivery Server Down Error

• Follow these solutions in order. Most users resolve this error within 20 minutes using Solutions 1-3.

Solution 1: Verify Email Address Format
The most common cause of the Delivery Server Down error is incorrect email formatting .

Step 1: Verify Company and Customer-Facing Email Addresses

• Click the Gear icon for Settings and select Account and Settings
• Move to the Company tab and choose Contact info
• Check both the Company email and Customer-facing email fields

Ensure the format is correct:

• Format
• Status
  mycompany@mycompany com
  Correct
  email:mycompany@mycompany com
  Incorrect

Remove any prefix like "email:" and ensure no extra spaces

Step 2: Verify Location Email Address (If Using Location Tracking)

• Go to Settings → All Lists → Locations
• Find the location used on the invoice
• Click Edit from the Action column

Verify the email address in the field: "This location has a different email address for communicating with customers"

• Update if needed and click Save
• Resend the sales form

Solution 2: Remove Special Characters from Invoice Fields

Special characters in invoice fields can trigger the Delivery Server Down error .

Step-by-Step Instructions:

• Open an existing invoice or create a new one

Remove any special characters from:

• Description
• Attachment name
• Message
• Email address
• Custom form templates
• Characters to remove:
• text
• ! @ # $ % ^ & * ( ) _ – = + : "
• Ensure all fields are free of these characters
• Save the invoice and try sending again

Solution 3: Check Sales Form Email Option

The email attachment setting may need adjustment .

Step-by-Step Instructions:

• Go to Settings → Account and Settings
• Select the Sales tab
• Find and select Online Delivery
• Check or uncheck the box next to PDF Attached
• Click Save and then Done
• Try resending the sales form

Solution 4: Verify Print and PDF Settings

Incorrect print and PDF settings can cause email delivery failures .

• Check Adobe Acrobat or Reader Settings:
• Open Adobe Acrobat/Reader

Ensure the following settings are correct :

• Page Size: Actual Size
• Orientation: Automatic
• Choose paper source by PDF page size: ON

Check Browser PDF Settings:

Google Chrome:

• Open Chrome → Settings → Privacy and Security
• Select Site Settings → Additional Content Settings
• Click PDF Documents

Turn OFF "Download PDF files instead of automatically opening them in Chrome"

Mozilla Firefox:

• Open Firefox → Options → Applications
• Scroll to Portable Document Format (PDF)
• Set the Action to Use Adobe Acrobat (or Adobe Reader)
• Close the tab and try sending again

Solution 5: Verify Email Settings in QuickBooks

Step-by-Step Instructions:

• Go to Settings → Account and Settings
• Select Company → Communications section
• Click Edit in the Email column
• Enter the correct email address and password
• Verify all other details are correct
• Click Save and then Done

Solution 6: Clear Browser Cache and Cookies

Excessive cache and cookies can cause server connection issues .
Google Chrome:

• Open Chrome and click More (three dots)
• Select More Tools → Clear browsing data
• Choose All Time for the time range

Check:

• Cached images and files
• Cookies and other site data
• Click Clear Data

Firefox:

• Open Firefox → Options → Privacy & Security
• Under Cookies and Site Data, click Clear Data
• Check Cached Web Content
• Click Clear and exit

Note: Log in to QuickBooks again and try sending the email. If the error persists, try using another supported browser .

Solution 7: Check Internet Connection and Firewall Settings

Network issues can trigger delivery errors .

Step-by-Step Instructions:

• Check Internet Stability – Test your connection by visiting a secure website
• Restart Router – Power cycle your router and modem
• Try Wired Connection – Use Ethernet instead of Wi-Fi for stability
• Check Firewall/Antivirus – Temporarily disable security software to test If the error resolves, add QuickBooks as an exception

Solution 8: Update QuickBooks Online
Outdated QuickBooks versions can cause compatibility issues .
Step-by-Step Instructions:

• Refresh your QuickBooks Online browser tab
• Clear cache and cookies (Solution 6)
• Try using a different supported browser:
• Google Chrome
• Mozilla Firefox
• Apple Safari
• Microsoft Edge

How to Prevent QuickBooks Delivery Server Down Error

Once resolved, take these steps to prevent future occurrences:

• Use Correct Email Formats – Always use company@domain dot com format without prefixes.
• Avoid Special Characters – Never use special characters in invoice fields, attachment names, or custom templates .
• Keep Attachments Small – Ensure attachments are under 25 MB, not ZIP files, and have clean filenames .
• Maintain Stable Internet – Use a wired connection for critical tasks.
• Update Browsers – Keep Google Chrome, Firefox, or Edge updated.
• Set Adobe as Default PDF Viewer – Ensure Adobe Acrobat/Reader is the default PDF application .
• Regularly Clear Cache – Clear browser cache and cookies monthly.
• Use Supported Browsers – Stick to Chrome, Firefox, Safari, or Edge for QuickBooks Online .

Frequently Asked Questions (QuickBooks Delivery Server Down Error)
Q1: What causes the QuickBooks Delivery Server Down Error?

• A: This error is typically caused by incorrect email formats, special characters in invoices, misconfigured PDF settings, large attachments, or security software blocking connections .

Q2: Why can't I send invoices from QuickBooks Online?

• A: Common reasons include incorrect email address format, special characters in invoice fields, browser PDF settings, or attachment issues .

Q3: How do I fix the "Unable to send your email" message in QuickBooks?

• A: Check your email format, remove special characters from invoices, verify your browser's PDF settings, and ensure your internet connection is stable .

Q4: Can special characters in invoices cause delivery errors?

• A: Yes. Special characters like ! @ # $ % ^ & * ( ) _ – = + : " in invoice descriptions, attachment names, or custom templates can trigger the Delivery Server Down error .

Q5: What should I do if the Delivery Server Down error persists?

• A: If basic troubleshooting doesn't work, contact QuickBooks support for advanced diagnostics. There may be a deeper issue with your email settings or QuickBooks configuration .

Q6: Does browser choice affect QuickBooks email delivery?

• A: Yes. QuickBooks Online works best with Google Chrome, Mozilla Firefox, Apple Safari, and Microsoft Edge. Incorrect browser PDF settings can cause delivery failures .

Quick Reference: Delivery Server Down Troubleshooting Guide

Symptom

• Most Likely Cause
• Solution
• Email not sending
• Incorrect email format

Solution 1 (Verify Email Format)

• Invoice fails to send
• Special characters in invoice

Solution 2 (Remove Special Characters)

• PDF not attaching
• Browser PDF settings

Solution 4 (Check PDF Settings)

• Attachment fails
• File too large or ZIP format
• Check file size (<25 MB) and format
• Cannot connect to server
  = Firewall/antivirus block

Solution 7 (Check Firewall)

• Error after browser update
• Cache corruption

Solution 6 (Clear Cache)

Need Professional Help? Contact Our QuickBooks Data Service Team

You have tried everything. You verified email formats. You removed special characters. You checked browser PDF settings. You cleared cache and cookies. You reviewed your firewall settings. And the QuickBooks Delivery Server Down error still appears.

At this point, the issue may be:

A deeper email configuration issue requiring expert diagnosis
A backend QuickBooks Online issue needing Intuit support
Complex network or security settings blocking email delivery
For direct assistance with QuickBooks Delivery Server Down Error, contact our QuickBooks Data Service Team at +1-(888)-718-7888.

When you call, have this information ready:

Your QuickBooks Online version
The exact error message you're seeing
Whether the error occurs with all customers or specific ones
A list of solutions you have already tried from this guide
Your browser and version

Tell the representative: "I have already verified my email format, removed special characters from invoices, checked my browser PDF settings, and cleared my cache. I need help with the QuickBooks Delivery Server Down error."

Final Thoughts: Keep Your Invoices Flowing

The QuickBooks Delivery Server Down error is frustrating because it blocks critical business communication. Customers don't receive invoices. Payments get delayed. Your workflow grinds to a halt.

Start with the simplest fixes: verify your email address format (Solution 1) and remove special characters from your invoices (Solution 2). These two solutions resolve the majority of Delivery Server Down cases.

If the error persists, check your browser PDF settings (Solution 4), ensure attachments are under 25 MB, and clear your browser cache (Solution 6). For persistent issues, review your firewall and security settings (Solution 7).

Remember these key points:

Correct email format is essential (company domain dot com, no prefixes)

• No special characters in invoice fields
• Browser PDF settings must be configured correctly
• Attachments must be under 25 MB
• Clearing cache often resolves connection issues

Your business runs on QuickBooks. Keep your invoices flowing - and your customers informed.

Need immediate help? Our QuickBooks Data Service Team is available to assist with Delivery Server Down errors and other email delivery issues. Call us at +1-(888)-718-7888 for expert troubleshooting and fast resolution of your QuickBooks email problems.