Microsoft 365 / Exchange Online Email Setup¶

Professional-level guide for integrating Microsoft 365 (Exchange Online) email with Odoo, including catchall addresses, mail flow rules, and OAuth2 authentication.

Architecture Overview¶

┌─────────────────────────────────────────────────────────────────────┐
│                 MICROSOFT 365 / EXCHANGE ONLINE                      │
└─────────────────────────────────────────────────────────────────────┘

                         Your Domain: yourdomain.com
                                    │
                    ┌───────────────┼───────────────┐
                    │               │               │
                    ▼               ▼               ▼
            ┌───────────┐   ┌───────────┐   ┌───────────┐
            │  Aliases  │   │ Catchall  │   │ Mail Flow │
            │           │   │ (Transport│   │   Rules   │
            │ sales@    │   │   Rule)   │   │           │
            │ support@  │   │     ↓     │   │ purchase+ │
            │ info@     │   │ catchall@ │   │ sale+     │
            └─────┬─────┘   └─────┬─────┘   └─────┬─────┘
                  │               │               │
                  └───────────────┼───────────────┘
                                  │
                                  ▼
                    ┌─────────────────────────┐
                    │  Shared/Service Mailbox │
                    │   odoo@yourdomain.com   │
                    └────────────┬────────────┘
                                 │
                    ┌────────────┼────────────┐
                    │            │            │
                    ▼            ▼            ▼
              ┌──────────┐ ┌──────────┐ ┌──────────┐
              │  IMAP    │ │   SMTP   │ │  Azure   │
              │ Incoming │ │ Outgoing │ │  OAuth2  │
              └────┬─────┘ └────┬─────┘ └────┬─────┘
                   │            │            │
                   └────────────┼────────────┘
                                │
                                ▼
                    ┌─────────────────────────┐
                    │         ODOO            │
                    │                         │
                    │  • Fetchmail Service    │
                    │  • mail.thread routing  │
                    │  • Email sending        │
                    └─────────────────────────┘

Prerequisites¶

Requirement	Description
Microsoft 365	Business Basic or higher (Exchange Online)
Admin Access	Exchange Admin or Global Admin
Azure AD Access	For OAuth2 app registration
Domain Verified	Custom domain configured in M365
Odoo Access	Admin access to Odoo instance

Key Differences from Google Workspace¶

Feature	Google Workspace	Microsoft 365
Catchall	Built-in feature	Transport rule workaround
Admin Portal	Google Admin Console	Exchange Admin Center + Azure Portal
OAuth Setup	Google Cloud Console	Azure Portal (Entra ID)
Pattern Routing	Default Routing rules	Mail Flow (Transport) rules
Shared Mailbox	User aliases	Shared Mailbox (no license)

Step 1: Create Service Account or Shared Mailbox¶

You have two options:

Option A: Shared Mailbox (No License Required)¶

Go to Exchange Admin Center
Navigate to Recipients → Mailboxes → Add a shared mailbox
Create mailbox:

Field	Value
Display name	Odoo System
Email address	odoo@yourdomain.com

Shared Mailbox Benefits

No license required (cost savings)
Up to 50GB storage
Multiple users can access

Option B: Service Account (Licensed User)¶

Go to Microsoft 365 Admin Center
Navigate to Users → Active users → Add a user
Create user:

Field	Value
Display name	Odoo Service
Username	odoo@yourdomain.com
License	Exchange Online (minimum)

Shared Mailbox + OAuth Limitation

Shared mailboxes require special OAuth configuration. For simpler setup, use a licensed service account.

Step 2: Enable IMAP and SMTP AUTH¶

For Individual Mailbox¶

Using PowerShell:

# Connect to Exchange Online
Connect-ExchangeOnline

# Enable IMAP
Set-CASMailbox -Identity "odoo@yourdomain.com" -ImapEnabled $true

# Enable SMTP AUTH (required for sending)
Set-CASMailbox -Identity "odoo@yourdomain.com" -SmtpClientAuthenticationDisabled $false

# Verify settings
Get-CASMailbox -Identity "odoo@yourdomain.com" | FL Imap*, Smtp*

For Organization-Wide (if SMTP AUTH is disabled)¶

# Check organization setting
Get-TransportConfig | FL SmtpClientAuthenticationDisabled

# Enable if needed (affects all users)
Set-TransportConfig -SmtpClientAuthenticationDisabled $false

Via Exchange Admin Center¶

Go to Recipients → Mailboxes
Select the Odoo mailbox
Click Manage email apps settings
Enable IMAP and Authenticated SMTP

Step 3: Set Up Catchall (Transport Rule Method)¶

Microsoft 365 doesn't have built-in catchall. Use transport rules instead.

Step 3.1: Create Dynamic Distribution Group¶

This group contains all valid recipients to exclude from catchall.

Using PowerShell:

# Connect to Exchange Online
Connect-ExchangeOnline

# Create Dynamic Distribution Group with all recipients
New-DynamicDistributionGroup -Name "All Mail Recipients" `
    -RecipientFilter "RecipientType -eq 'UserMailbox' -or RecipientType -eq 'MailUniversalDistributionGroup' -or RecipientType -eq 'MailUniversalSecurityGroup' -or RecipientType -eq 'MailContact' -or RecipientType -eq 'SharedMailbox'"

# Verify members
$DDG = Get-DynamicDistributionGroup "All Mail Recipients"
Get-Recipient -RecipientPreviewFilter $DDG.RecipientFilter | Select Name, PrimarySmtpAddress

Step 3.2: Change Domain to Internal Relay¶

This allows Exchange to accept emails for non-existent addresses.

Using PowerShell:

# View current domain type
Get-AcceptedDomain | FL Name, DomainType

# Change to Internal Relay
Set-AcceptedDomain -Identity "yourdomain.com" -DomainType InternalRelay

Via Exchange Admin Center:

Go to Mail flow → Accepted domains
Select your domain
Change type to Internal Relay

Internal Relay Impact

This allows ALL emails to your domain to be accepted, even to non-existent addresses. Make sure your catchall rule is working before enabling this.

Step 3.3: Create Transport Rule for Catchall¶

Via Exchange Admin Center:

Go to Mail flow → Rules
Click + Add a rule → Create a new rule
Configure:

Setting	Value
Name	Catchall to Odoo
Apply this rule if	The recipient is not a member of "All Mail Recipients"
Do the following	Redirect the message to odoo@yourdomain.com
Except if	The sender is inside the organization
Priority	Set lower than other rules

Using PowerShell:

New-TransportRule -Name "Catchall to Odoo" `
    -SentToMemberOf "All Mail Recipients" `
    -ExceptIfSentToMemberOf "All Mail Recipients" `
    -RedirectMessageTo "odoo@yourdomain.com" `
    -Priority 10

Dynamic Group Update Delay

Microsoft updates Dynamic Distribution Groups once per day. New users may not receive email until the next update. Force update with:

Set-DynamicDistributionGroup "All Mail Recipients" -RecipientFilter $((Get-DynamicDistributionGroup "All Mail Recipients").RecipientFilter)

(Limited to once per hour)

Step 4: Set Up Pattern-Based Routing (Recommended)¶

Instead of catchall, route specific Odoo patterns for better control.

Create Mail Flow Rules for Odoo Patterns¶

Rule 1: Purchase Order Replies

Go to Mail flow → Rules → + Add a rule
Configure:

Setting	Value
Name	Route Purchase+ to Odoo
Apply this rule if	The recipient address includes: `purchase+`
Do the following	Redirect the message to: odoo@yourdomain.com

Rule 2: Sales Order Replies

Setting	Value
Name	Route Sale+ to Odoo
Apply this rule if	The recipient address includes: `sale+`
Do the following	Redirect the message to: odoo@yourdomain.com

Rule 3: Helpdesk Replies

Setting	Value
Name	Route Helpdesk+ to Odoo
Apply this rule if	The recipient address includes: `helpdesk+`
Do the following	Redirect the message to: odoo@yourdomain.com

Using PowerShell (All Rules):

# Purchase Orders
New-TransportRule -Name "Route Purchase+ to Odoo" `
    -RecipientAddressContainsWords "purchase+" `
    -RedirectMessageTo "odoo@yourdomain.com"

# Sales Orders
New-TransportRule -Name "Route Sale+ to Odoo" `
    -RecipientAddressContainsWords "sale+" `
    -RedirectMessageTo "odoo@yourdomain.com"

# Helpdesk
New-TransportRule -Name "Route Helpdesk+ to Odoo" `
    -RecipientAddressContainsWords "helpdesk+" `
    -RedirectMessageTo "odoo@yourdomain.com"

# CRM Leads
New-TransportRule -Name "Route CRM+ to Odoo" `
    -RecipientAddressContainsWords "crm+","lead+" `
    -RedirectMessageTo "odoo@yourdomain.com"

Combined Rule with Regex¶

For advanced pattern matching:

New-TransportRule -Name "Route All Odoo Patterns" `
    -RecipientAddressMatchesPatterns "^(purchase|sale|helpdesk|crm|lead|project)\+.*@yourdomain\.com$" `
    -RedirectMessageTo "odoo@yourdomain.com"

Step 5: Configure Azure OAuth2 for Odoo¶

Microsoft deprecated Basic Auth. Use OAuth2 for secure authentication.

Step 5.1: Register Application in Azure Portal¶

Go to Azure Portal
Navigate to Microsoft Entra ID (formerly Azure Active Directory)
Click App registrations → New registration
Configure:

Field	Value
Name	Odoo Mail Integration
Supported account types	Accounts in this organizational directory only
Redirect URI	Web: `https://yourodoo.com/microsoft_outlook/confirm`

Click Register
Copy the Application (client) ID and Directory (tenant) ID

Step 5.2: Create Client Secret¶

In your app registration, go to Certificates & secrets
Click New client secret
Add description: Odoo OAuth
Set expiration (24 months recommended)
Click Add
Copy the secret value immediately (won't be shown again)

Step 5.3: Configure API Permissions¶

Go to API permissions
Click Add a permission
Select Microsoft Graph
Choose Delegated permissions
Add these permissions:

Permission	Purpose
`User.Read`	Sign in and read user profile
`IMAP.AccessAsUser.All`	Read email via IMAP
`SMTP.Send`	Send email via SMTP
`offline_access`	Maintain access (refresh token)

Click Add permissions
Click Grant admin consent for [Your Organization]

Step 5.4: Add Users to Application (Optional)¶

For additional security:

Go to Enterprise applications
Find your Odoo Mail Integration app
Go to Users and groups
Click Add user/group
Add the Odoo service account

Step 6: Configure Odoo¶

Install Microsoft Outlook Module¶

Go to Apps
Search for Microsoft Outlook
Install the module

Configure OAuth Credentials¶

Go to Settings → General Settings
Enable Custom Email Servers under Discuss
Enter OAuth credentials:

Field	Value
Client ID	(from Azure Portal)
Client Secret	(from Azure Portal)

Click Save

Configure Outgoing Mail Server¶

Go to Settings → Technical → Outgoing Mail Servers
Create new server:

Field	Value
Description	Microsoft 365 OAuth
SMTP Server	smtp.office365.com
SMTP Port	587
Connection Security	TLS (STARTTLS)
Username	odoo@yourdomain.com
Outlook OAuth Authentication	Checked

Click Connect your Outlook account
Complete Microsoft authentication
Click Test Connection

Configure Incoming Mail Server¶

Go to Settings → Technical → Incoming Mail Servers
Create new server:

Field	Value
Name	Microsoft 365 OAuth IMAP
Server Type	Outlook OAuth Authentication
Username	odoo@yourdomain.com
Outlook OAuth Authentication	Checked

Click Connect your Outlook account
Click Test & Confirm

Alternative: Basic Auth (Not Recommended)¶

If OAuth isn't possible, use SMTP Relay:

Outgoing Server:

Field	Value
SMTP Server	yourdomain-com.mail.protection.outlook.com
SMTP Port	25
Connection Security	TLS (STARTTLS)
Username	(leave empty for relay)

Basic Auth Deprecation

Microsoft is phasing out Basic Authentication. Use OAuth2 for new setups.

Step 7: Configure Odoo Alias Domain¶

Go to Settings → General Settings
Under Discuss, set Alias Domain: yourdomain.com
Click Save

Step 8: Verify Fetchmail Cron¶

Go to Settings → Technical → Scheduled Actions
Find Mail: Fetchmail Service
Verify:

Setting	Value
Active	Checked
Interval	5 minutes

Testing the Setup¶

Test 1: Send Email from Odoo¶

Create a Purchase Order
Send RFQ to test email
Verify email received
Check headers for correct Reply-To

Test 2: Reply Routing¶

Reply to the RFQ email
Wait for fetchmail (or run manually)
Check if reply appears in PO chatter

Test 3: Pattern Routing¶

Send email to purchase+test@yourdomain.com
Verify it arrives in Odoo mailbox

Test 4: Catchall (if configured)¶

Send email to random123@yourdomain.com
Verify it arrives in Odoo mailbox

Troubleshooting¶

OAuth Connection Failed¶

Issue	Solution
Redirect URI mismatch	Must match exactly in Azure and Odoo
Missing permissions	Grant admin consent in Azure
Wrong tenant	Verify Directory (tenant) ID
HTTPS required	Odoo must use HTTPS for OAuth

Emails Not Being Received¶

Issue	Solution
IMAP disabled	Enable in Exchange Admin Center
Transport rule not working	Check rule priority and conditions
Domain not Internal Relay	Change domain type in Accepted Domains
DDG not updated	Force update or wait 24 hours

Cannot Send Emails¶

Issue	Solution
SMTP AUTH disabled	Enable per-mailbox or org-wide
Authentication failed	Re-authenticate OAuth in Odoo
Relay blocked	Check connector settings

Check Message Trace¶

Go to Exchange Admin Center
Navigate to Mail flow → Message trace
Search for specific email addresses
View delivery status and applied rules

PowerShell Diagnostics¶

# Check mailbox settings
Get-CASMailbox -Identity "odoo@yourdomain.com" | FL

# Check transport rules
Get-TransportRule | FL Name, State, Priority

# Check accepted domains
Get-AcceptedDomain | FL Name, DomainType

# Test mail flow
Test-Mailflow -TargetEmailAddress "test@external.com"

# View message trace
Get-MessageTrace -RecipientAddress "odoo@yourdomain.com" -StartDate (Get-Date).AddDays(-1)

Complete Configuration Summary¶

Exchange Admin Center¶

Setting	Location	Value
Odoo Mailbox	Recipients → Mailboxes	odoo@yourdomain.com
IMAP Enabled	Mailbox → Email apps	Enabled
SMTP AUTH	Mailbox → Email apps	Enabled
Domain Type	Mail flow → Accepted domains	Internal Relay
Transport Rules	Mail flow → Rules	Catchall + Pattern rules

Azure Portal¶

Setting	Location	Value
App Registration	Entra ID → App registrations	Odoo Mail Integration
Client Secret	App → Certificates & secrets	Created
API Permissions	App → API permissions	IMAP, SMTP, User.Read
Redirect URI	App → Authentication	https://yourodoo.com/microsoft_outlook/confirm

Odoo¶

Setting	Location	Value
Outlook module	Apps	Installed
OAuth credentials	General Settings	Client ID + Secret
Alias domain	General Settings → Discuss	yourdomain.com
Outgoing server	Technical → Outgoing Mail	Microsoft 365 OAuth
Incoming server	Technical → Incoming Mail	Microsoft 365 OAuth IMAP
Fetchmail cron	Technical → Scheduled Actions	Active, 5 min

Security Best Practices¶

Practice	Description
Use OAuth2	Never use Basic Auth in production
Service account	Dedicated account for Odoo
Conditional Access	Apply Azure AD policies to app
Audit logs	Enable mailbox audit logging
Secret rotation	Rotate client secrets before expiry
MFA exemption	May need to exempt service account from MFA

Monthly Maintenance Checklist¶

Verify fetchmail cron is running
Check OAuth token is still valid
Check client secret expiry date
Review transport rules are working
Check message trace for delivery issues
Verify DDG membership is current
Check Odoo mailbox storage quota

PowerShell Quick Reference¶

# Connect to Exchange Online
Connect-ExchangeOnline

# Enable IMAP/SMTP for mailbox
Set-CASMailbox -Identity "odoo@yourdomain.com" -ImapEnabled $true -SmtpClientAuthenticationDisabled $false

# Create transport rule
New-TransportRule -Name "Route to Odoo" -RecipientAddressContainsWords "purchase+" -RedirectMessageTo "odoo@yourdomain.com"

# Check transport rules
Get-TransportRule | Select Name, State, Priority

# Message trace
Get-MessageTrace -RecipientAddress "odoo@yourdomain.com" -StartDate (Get-Date).AddDays(-1)

# Force DDG update
Set-DynamicDistributionGroup "All Mail Recipients" -RecipientFilter $((Get-DynamicDistributionGroup "All Mail Recipients").RecipientFilter)

# Disconnect
Disconnect-ExchangeOnline

Microsoft 365 / Exchange Online Email Setup¶

Architecture Overview¶

Prerequisites¶

Key Differences from Google Workspace¶

Step 1: Create Service Account or Shared Mailbox¶

Option A: Shared Mailbox (No License Required)¶

Option B: Service Account (Licensed User)¶

Step 2: Enable IMAP and SMTP AUTH¶

For Individual Mailbox¶

For Organization-Wide (if SMTP AUTH is disabled)¶

Via Exchange Admin Center¶

Step 3: Set Up Catchall (Transport Rule Method)¶

Step 3.1: Create Dynamic Distribution Group¶

Step 3.2: Change Domain to Internal Relay¶

Step 3.3: Create Transport Rule for Catchall¶

Step 4: Set Up Pattern-Based Routing (Recommended)¶

Create Mail Flow Rules for Odoo Patterns¶

Combined Rule with Regex¶

Step 5: Configure Azure OAuth2 for Odoo¶

Step 5.1: Register Application in Azure Portal¶

Step 5.2: Create Client Secret¶

Step 5.3: Configure API Permissions¶

Step 5.4: Add Users to Application (Optional)¶

Step 6: Configure Odoo¶

Install Microsoft Outlook Module¶

Configure OAuth Credentials¶

Configure Outgoing Mail Server¶

Configure Incoming Mail Server¶

Alternative: Basic Auth (Not Recommended)¶

Step 7: Configure Odoo Alias Domain¶

Step 8: Verify Fetchmail Cron¶

Testing the Setup¶

Test 1: Send Email from Odoo¶

Test 2: Reply Routing¶

Test 3: Pattern Routing¶

Test 4: Catchall (if configured)¶

Troubleshooting¶

OAuth Connection Failed¶

Emails Not Being Received¶

Cannot Send Emails¶

Check Message Trace¶

PowerShell Diagnostics¶

Complete Configuration Summary¶

Exchange Admin Center¶

Azure Portal¶

Odoo¶

Security Best Practices¶

Monthly Maintenance Checklist¶

PowerShell Quick Reference¶

Sources¶