What it catches:
- Typos of big providers: [email protected] gets "Did you mean [email protected]?"
- Dead domains: domains that don't exist, have no mail server, or accept no email.
- Throwaway addresses: Mailinator, 10minutemail and thousands more, including their subdomains.
- Optional: shared inboxes (info@, sales@) and free providers, for sites that want work addresses.

It runs on your own server. No account, no API key, no limits, and nothing is sent to BounceLens. Only the domain name is looked up through your server's normal DNS. If DNS doesn't answer, the address is accepted, so a slow resolver never locks people out. The plugin stores nothing and adds no links or tracking to your site.

Settings: choose which forms are checked, what to block, an "always allow" list of domains, and whether to check in the administrator too. Joomla's own checks ("already in use", banned addresses) keep working. Developers can add validate="bouncelens" to an email field in their own form XML.

Two builds: Joomla 4.4, 5 and 6, and Joomla 3.9/3.10. Updates come through Joomla's normal update manager, and each Joomla version only gets the matching download.

Note: it can't tell whether a mailbox really exists. That needs a conversation with the receiving mail server, which this plugin does not do.