With OneMob, you can give your Outlook users access to send emails from inside OneMob — but routed through Outlook, so they come from your company's own email server rather than OneMob's.
Setup happens in two places: your Microsoft 365 / Outlook admin settings and your OneMob admin settings. Complete the Outlook steps first.
Part 1: Outlook (Microsoft 365) Settings
Step 1: Allow open relay from OneMob's IP
Whitelist OneMob's IP address — 34.214.115.223 — on your SMTP server so it's permitted to relay mail through your domain. See Microsoft's guide on enabling SMTP relay in Office 365.
Step 2: Create a bounce-handling mailbox
Create a new mailbox in Outlook with the address onemob-bounced@yourcompany.com (replace "yourcompany.com" with your actual domain). This will be used as the return path for bounced emails.
Step 3: Forward bounced emails to OneMob
Set up forwarding so all emails sent to onemob-bounced@yourcompany.com are also forwarded to bounced@onemob.com. This allows OneMob to track bounces on your behalf.
Step 4: Whitelist OneMob's domain
Whitelist @onemob.com so your users reliably receive email invites and notifications from OneMob.
Part 2: OneMob Settings
- As a OneMob Admin, go to Admin Settings.
- Click SMTP Settings.
- Toggle SMTP Settings on.
- Enter the following:
| Field | Value |
|---|---|
| IP or Host | smtp.office365.com |
| Port |
587 (confirm with your IT admin — some Microsoft 365 relay setups use port 25 instead; see Part 1, Step 1)
|
| Domain | Your website without "www." (e.g., onemob.com) |
| Return path for bounced emails | The bounce address from Part 1, Step 2 (e.g., onemob-bounced@yourcompany.com) |
| User Name / Password | Leave blank for most setups |
- Click Save Changes.
Test the Integration
Send a New Email from OneMob to an email address you have access to, and confirm the "From" address matches the login email of the OneMob account that sent it.
*Not Available on Forever Free Plan
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