codigoed

Little Message Lite is a lightweight WordPress plugin that adds a floating button to your site. When clicked, it opens a compact contact form so visitors can send you a quick message via email — no page reloads required.
Messages are also stored in your WordPress database for easier access and backup.
Just set your email address, and you’re ready to go. Ideal for portfolios, simple sites, landing pages, or anyone who needs a fast and clean way to receive messages.
Includes optional reCAPTCHA v2 or v3 to prevent spam, plus customizable design and display options.
Upgrade to PRO to reply to messages from your WordPress admin, unlock advanced display rules, and add more contact methods like Telegram or Messenger.
<h3>Upgrade to PRO</h3>
Need more features? Upgrade to <a href="https://codigo-ed.com/plugin-mensajito/" rel="nofollow ugc">Little Message PRO</a> and unlock:
<ul>
<li>Reply to messages from the WordPress admin</li>
<li>Customize where and when the button appears</li>
<li>Add Telegram and Messenger contact options</li>
</ul>
<h3>License</h3>
This plugin is free software licensed under GPLv2 or later. 
You may modify, distribute, and use it commercially or personally. 
More info: https://www.gnu.org/licenses/gpl-2.0.html

Little Message Lite

Lightweight contact form with floating button, email alerts, anti-spam, and simple setup. Ideal for small sites.

quan_flo

If there is a user (or a bot) that signed up at your site this user can start to send messages to every other user. 
I had some negative experiences with this and so I wrote a module that should help to block such a spam.
Buddypress Messages Spam Blocker introduces some restrictions to your users:
<ul>
<li>New users can send messages only 24h after their registration, so you’ll have time if bot registrations have to be removed manually (modify this value using filter ‘buddypress_messages_spamblocker_newMembersWaitingPeriod’)</li>
</ul>
Their are also some more restrictions for mass mailings (mails that are sent to “friends” of the contact list are not included in this calculation):
<ul>
<li>Users can send 6 messages maximum in 5 minutes (modify this value using filter ‘buddypress_messages_spamblocker_5m’)</li>
<li>Users can send 10 messages maximum in 10 minutes (modify this value using filter ‘buddypress_messages_spamblocker_10m’)</li>
<li>Users can send 20 messages maximum in 30 minutes (modify this value using filter ‘buddypress_messages_spamblocker_30m’)</li>
<li>Users can send 30 messages maximum in 60 minutes (modify this value using filter ‘buddypress_messages_spamblocker_60m’)</li>
<li>Users can send 35 messages maximum in 12 hours (modify this value using filter ‘buddypress_messages_spamblocker_12h’)</li>
<li>Users can send 45 messages maximum in 24 hours (modify this value using filter ‘buddypress_messages_spamblocker_24h’)</li>
<li>Users can send 50 messages maximum in 48 hours (modify this value using filter ‘buddypress_messages_spamblocker_48h’)</li>
</ul>
Users with the capability “edit_users” (admins etc.) have no restrictions for outgoing messages
Install, activate, and it will work.
More about me and my plugins
Since the year 1999 I do administration, customizing and programming for several forums, communities and social networks. In the year 2013 I switched from another PHP framework to WordPress. 
Because not all plugins I’d like to have exist already I wrote some own plugins and I think I’ll continue to do so.
If you have the scope at forums or social networks my other modules might also be interesting for you. <a href="https://wordpress.org/plugins/search.php?q=quan_flo" title="ifs-net / quan_flo WordPress Plugins" rel="ugc">Just take a look at my WordPress Profile to see all my Plugins.</a> Use them and if my work helps you to save time, earn money or just makes you happy feel free to donate – Thanks. The donation link can be found at the right sidebar next to this text.

Buddypress Messages Spam Blocker

This plugin will block mass mailing for the buddypress messaging system

Little Message Lite vs Buddypress Messages Spam Blocker