Brajesh, again thanks for the quick response!

I tested on two staging servers with different versions of WP/BP (single site). The plugin did not seem to work on an older version of WP/BP. After testing, I realized that the plugin description requires BP 2.4+ … of course!

WP 4.4.1 / BP 2.3.3 / PHP 5.4.45

On the first test, the plugin did not seem to work at all. I created multiple regular user test accounts. I set the rate limiter for 3 NEW messages in 3 minutes. I was able to send to 4+ users simultaneously and then repeatedly to individual and multiple users. I used the same and different subject lines. The rate limit was never triggered.

WP 4.4.2 / BP 2.4.3 / PHP 5.5.9

On the second test server, the plugin seemed to work as described (with one exception). The rate limit was triggered if I sent consecutive messages to individual or multiple users.

However, I was able to send a single message to 7+ users. I realize it is not the design of this plugin to limit the number of recipients, but it does seem to be a hole for spam. I wish there was a way to limit the number of recipients of a PM (preferably to 1).

__________

For us it would be best if we had a plugin that limits PM’s to friends and/or followers only. There were two old plugins created by r-a-y that did this, but they haven’t been updated in about 5 years.

https://wordpress.org/plugins/buddypress-private-message-for-friends-only/
https://github.com/wpaustralia/wpaustralia/tree/master/plugins/buddypress-private-message-for-friends-only

https://wordpress.org/plugins/buddypress-private-messages-for-followers-only/
https://github.com/r-a-y/bp-pms-for-followers

We would gladly pay for updated plugins with this functionality.

__________

Thanks again! I hope this test info is helpful.

Thanks for the quick reply. If you mean that the plugin should limit the number of new conversation threads within the set time period (regardless of how many recipients), then it does not seem to be working as expected.

What I mean is that User1 can exceed the plugin rate limit by sending multiple messages – one after the other – to User2 (doesn’t matter if the subject is the same or different).

Is that expected behavior?

Here are the details about our installation:

WordPress / BuddyPress:

WordPress: 4.4.2
WordPress multisite: no
BuddyPress: 2.4.3
MySQL: 5.6.28
PHP: 5.5.9-1ubuntu4.14
Permalinks: custom

Theme:

Current theme: CBOX Child Theme version 1.0
Infinity Version: 1.1b
Developer Mode: Enabled

Active Plugins:

Akismet: 3.1.7
bbPress: 2.5.8
Better Font Awesome: 1.4.3
BP Auto Login on Activation: 1.0.1
BP Display Name: 1.0
BP Group Announcements: 1.0.5
BuddyPress Auto Group Join: 2.2.1
BuddyPress Group Email Subscription: 3.6.0
CAC Featured Content: 1.0.6
CloudFlare: 1.3.20
Commons In A Box: 1.0.12
Contact Form 7: 4.4
CUNY Academic Commons Buddy Press Admin Bar Mods: 0.1
Custom Post Type Editor: 1.2.5
Custom Profile Filters for BuddyPress: 0.3.1
Display Widgets: 2.05
Export User Data: 1.2.0
GD bbPress Attachments: 2.3.1
Google Analytics by Yoast: 5.4.6
Google Language Translator: 5.0.05
Gravity Forms: 1.9.16
Gravity Forms MailChimp Add-On: 3.7.1
Gravity Forms No CAPTCHA reCAPTCHA: 1.0.7
Gravity Forms User Registration Add-On: 3.1
Invite Anyone: 1.3.9
Login Logo: 0.7
Page Links To: 2.9.6
Page Restrict: 2.2.6
Pantheon Migration: 1.20
Really Simple CAPTCHA: 1.8.0.1
SearchWP: 2.7
SearchWP bbPress Integration: 0.1
SeedProd Coming Soon Pro: 3.10.1
Stream: 3.0.4
valet.io: 4.1.28
VaultPress: 1.7.9
Widget CSS Classes: 1.3.0
WordPress HTTPS: 3.3.6
WordPress Importer: 0.6.1
WP-Ban: 1.68
WP-ShowHide: 1.04
WP Better Emails: 0.3
WP Crontrol: 1.3
wpMandrill: 1.33
WP Migrate DB Pro: 1.5.5
WP Snippets: 150201
WP Valet Mail Logger: 0.01
Yoast SEO: 3.0.7