WPO365 | Mail Integration for Office 365 / Outlook
Early November 2022, ownership of the Mail Integration for Office 365 / Outlook plugin transferred to WPO365. We are committed to provide (best-effort based) support for this plugin until the end of 2023.
Use with caution
WPO365 works, but test it on a staging site before relying on it in 2026. It runs on 1K+ sites, is rated 4.9/5 and was last updated 2 years ago, and scores 44/100 on our health check.
- Loved by users — 4.9/5 from 26 reviews
- No update in 2 years
- Only tested up to WordPress 6.1 (latest is 7.1)
Daily downloads
Download spikes usually follow a new release — each site that auto-updates counts as a download.
Rankings
Where WPO365 stands todayWordPress.org search rankings
Live position in the plugin search, top 100| Keyword | Position |
|---|---|
| 365 smtp | #30 |
| live smtp | >100 |
| oauth | >100 |
| outlook smtp | #57 |
| smtp | >100 |
Version adoption
Share of active sites per release.
Rating breakdown
★★★★★★★★★★ 4.9 from 26 reviews
About WPO365
From the official readme · v1.9.2Description
Support ending
= Support ending =
Early November 2022, ownership of the Mail Integration for Office 365 / Outlook plugin transferred to WPO365. We are committed to provide (best-effort based) support for this plugin until the end of 2023.
To ensure, however, that we are able to provide you with long time support, we urge you to download and install the WPO365 | MICROSOFT GRAPH MAILER plugin for WordPress instead (and de-activate the Mail Integration for Office 365 / Outlook plugin and remove it from your WordPress website).
If you have already installed and configured the Mail Integration for Office 365 / Outlook plugin, then please make sure to check out our easy-to-understand online migration guide.
Marco van Wieren | Downloads by van Wieren | https://www.wpo365.com/
About this plugin
Mail Integration for Office 365/Outlook (using OAuth2 and Microsoft’s Graph API rather than SMTP)
This plugin addresses the limitations of current free SMTP plugins, allowing you to send email from WordPress via your Microsoft Account and ensure your email gets delivered reliably, avoiding the spam box! Note, unlike other free SMTP plugins, this one authenticates with the Microsoft Graph API rather than SMTP using OAuth2. This addresses the recent change by Microsoft to disable basic authentication over SMTP (i.e. username and password), preventing other free SMTP plugins from working with Microsoft Accounts. Unfortunately, Microsoft has yet to enable their Graph API to work with the free versions of Outlook, Live, Hotmail etc. The plugin should however work with the paid for personal and business versions of Office 365, Outlook and Microsoft Exchange.
WPO365 | Mail Integration for Office 365 / Outlook
Contributors: wpo365
Tags: smtp, outlook smtp, 365 smtp, live smtp, oauth
Requires at least: 5.5.3
Tested up to: 6.1
Stable tag: 1.9.2
Requires PHP: 7.1.1
License: GPLv2 or later
License URI: http://www.gnu.org/licenses/gpl-2.0.html
IMPORTANT – Please choose the WPO365 | MICROSOFT 365 GRAPH MAILER plugin instead. This plugin is no longer supported and does not receive updates.
Setup Instructions
You will need to follow the steps outlined on the following website to setup this plugin correctly: https://docs.wpo365.com/article/164-mail-integration-365-wordpress-plugin
Setup Instructions
You will need to follow the steps outlined on the following website to setup this plugin correctly: https://docs.wpo365.com/article/164-mail-integration-365-wordpress-plugin
Installation
You will need to follow the steps outlined on the following website to setup this plugin correctly: https://docs.wpo365.com/article/164-mail-integration-365-wordpress-pluginYou will need to follow the steps outlined on the following website to setup this plugin correctly: https://docs.wpo365.com/article/164-mail-integration-365-wordpress-plugin
Changelog
Ver. 1.9.2 – Changed short description
Ver. 1.9.1 – Fixes an XSS vulnerability reported by patchstack in April 2023.
Ver. 1.9.0 – Ownership of the plugin transferred to WPO365 and tested with WordPress 6.1 / PHP 8.0
Ver. 1.8.6 – Corrected typo of atts filter variable to args
Ver. 1.8.5 – Added code to handle empty to, cc, bc and reply to email addresses, as well as adding an admin error if wp_mail is utilised by another plugins
Ver. 1.8.4 – Added Important Updates! notification to alert users to need to re-authenticate with Office 365
Ver. 1.8.3 – Addressed composer dependency issues by using php-scoper to namespace php libraries. Also addressed empty email array bug.
Ver. 1.8.2 – Modified wp_mail plugable function to address various issues with closing SMTP mail events and forwarding to the Graph API
Ver. 1.7.1 – Fixed undefined variable error for $cc, $bcc and $reply_to in older PHP versions
Ver. 1.7.0 – Fixed WooCommerce and HTML issue
Ver. 1.6.0 – Fixed email content type issue, invalid oauth state issue, and reply-to and send as bug
Ver. 1.5.0 – Fixed additional multisite bug and reply-to bug
Ver. 1.4.0 – Fixed bug where multisite options were unsupported
Ver. 1.3.0 – Changed error and OAuth scope handling.
Ver. 1.2.0 – Added support for sending attachments <3MB in size. Fixed session bug with WordPress API.
Ver. 1.1.0 – Added prefix namespace to composer libraries to avoid conflicts with other plugins using Guzzle whilst also updating the oauth2-azure library at the same time.
Ver. 1.0.4 – Fixed issue with code running outside of settings page, leading to error messages on admin backend. Replaced localhost with 127.0.0.1 if present in redirect URI to prevent potential hostname resolution issues. Updated to handle multiple “to” email addresses (either as a comma separated string, or a one dimensional array)
Ver. 1.0.3 – Fixed issue with send as feature, preventing emails being sent on behalf of others.
Ver. 1.0.2 – Updated readme.txt description and tags.
Ver. 1.0.1 – Fixed minor spelling and display issues.
Early November 2022, ownership of the Mail Integration for Office 365 / Outlook plugin transferred to WPO365. We are committed to provide (best-effort based) support for this plugin until the end of 2023.
To ensure, however, that we are able to provide you with long time support, we urge you to download and install the WPO365 | MICROSOFT GRAPH MAILER plugin for WordPress instead (and de-activate the Mail Integration for Office 365 / Outlook plugin and remove it from your WordPress website).
If you have already installed and configured the Mail Integration for Office 365 / Outlook plugin, then please make sure to check out our easy-to-understand online migration guide.
Marco van Wieren | Downloads by van Wieren | https://www.wpo365.com/
About this plugin
Mail Integration for Office 365/Outlook (using OAuth2 and Microsoft’s Graph API rather than SMTP)
This plugin addresses the limitations of current free SMTP plugins, allowing you to send email from WordPress via your Microsoft Account and ensure your email gets delivered reliably, avoiding the spam box! Note, unlike other free SMTP plugins, this one authenticates with the Microsoft Graph API rather than SMTP using OAuth2. This addresses the recent change by Microsoft to disable basic authentication over SMTP (i.e. username and password), preventing other free SMTP plugins from working with Microsoft Accounts. Unfortunately, Microsoft has yet to enable their Graph API to work with the free versions of Outlook, Live, Hotmail etc. The plugin should however work with the paid for personal and business versions of Office 365, Outlook and Microsoft Exchange.
https://youtu.be/EvNajsDenZMVer. 1.9.2 – Changed short description
Ver. 1.9.1 – Fixes an XSS vulnerability reported by patchstack in April 2023.
Ver. 1.9.0 – Ownership of the plugin transferred to WPO365 and tested with WordPress 6.1 / PHP 8.0
Ver. 1.8.6 – Corrected typo of atts filter variable to args
Ver. 1.8.5 – Added code to handle empty to, cc, bc and reply to email addresses, as well as adding an admin error if wp_mail is utilised by another plugins
Ver. 1.8.4 – Added Important Updates! notification to alert users to need to re-authenticate with Office 365
Ver. 1.8.3 – Addressed composer dependency issues by using php-scoper to namespace php libraries. Also addressed empty email array bug.
Ver. 1.8.2 – Modified wp_mail plugable function to address various issues with closing SMTP mail events and forwarding to the Graph API
Ver. 1.7.1 – Fixed undefined variable error for $cc, $bcc and $reply_to in older PHP versions
Ver. 1.7.0 – Fixed WooCommerce and HTML issue
Ver. 1.6.0 – Fixed email content type issue, invalid oauth state issue, and reply-to and send as bug
Ver. 1.5.0 – Fixed additional multisite bug and reply-to bug
Ver. 1.4.0 – Fixed bug where multisite options were unsupported
Ver. 1.3.0 – Changed error and OAuth scope handling.
Ver. 1.2.0 – Added support for sending attachments <3MB in size. Fixed session bug with WordPress API.
Ver. 1.1.0 – Added prefix namespace to composer libraries to avoid conflicts with other plugins using Guzzle whilst also updating the oauth2-azure library at the same time.
Ver. 1.0.4 – Fixed issue with code running outside of settings page, leading to error messages on admin backend. Replaced localhost with 127.0.0.1 if present in redirect URI to prevent potential hostname resolution issues. Updated to handle multiple “to” email addresses (either as a comma separated string, or a one dimensional array)
Ver. 1.0.3 – Fixed issue with send as feature, preventing emails being sent on behalf of others.
Ver. 1.0.2 – Updated readme.txt description and tags.
Ver. 1.0.1 – Fixed minor spelling and display issues.
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FAQ
WPO365: quick answers
Straight answers, pulled from live WordPress.org data.
Live data from WordPress.org · checked Sep 28, 2026
Is WPO365 free?
Yes. WPO365 is free to download and use from the official WordPress.org plugin directory.
Is WPO365 safe to use in 2026?
WPO365 works, but test it on a staging site before relying on it in 2026. It runs on 1K+ sites, is rated 4.9/5 and was last updated 2 years ago, and scores 44/100 on our health check.
How many websites use WPO365?
WPO365 is active on 1K+ WordPress websites and has been downloaded 60,499 times since it launched in November 2020. It was downloaded 273 times in the last 30 days.
Does WPO365 work with WordPress 7.1?
WPO365 is officially tested up to WordPress 6.1.14, while the latest release is 7.1.2. It may still work, but try it on a staging site first.
What PHP version does WPO365 need?
WPO365 requires PHP 7.1.1 or higher. Most hosts run PHP 8.x today, so it works on any modern WordPress hosting.
When was WPO365 last updated?
The latest version, 1.9.2, was released on June 20, 2024 (2 years ago).
Who makes WPO365?
WPO365 is developed and maintained by Marco van Wieren.
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