A problem occurred sending email, please contact your administrator. about registration HOT 4 CLOSED

exception 'Exception' with message 'Failed recipients: Array ( [0] => [email protected] ) ' in /home/www/fshareit.com/fshareit/apps/registration/controller/registercontroller.php:318 Stack trace: #0 /home/www/fshareit.com/fshareit/apps/registration/controller/registercontroller.php(145): OCA\Registration\Controller\RegisterController->sendValidationEmail('GGXK48', '[email protected]') #1 [internal function]: OCA\Registration\Controller\RegisterController->validateEmail() #2 /home/www/fshareit.com/fshareit/lib/private/AppFramework/Http/Dispatcher.php(159): call_user_func_array(Array, Array) #3 /home/www/fshareit.com/fshareit/lib/private/AppFramework/Http/Dispatcher.php(89): OC\AppFramework\Http\Dispatcher->executeController(Object(OCA\Registration\Controller\RegisterController), 'validateEmail') #4 /home/www/fshareit.com/fshareit/lib/private/AppFramework/App.php(99): OC\AppFramework\Http\Dispatcher->dispatch(Object(OCA\Registration\Controller\RegisterController), 'validateEmail') #5 /home/www/fshareit.com/fshareit/lib/private/AppFramework/Routing/RouteActionHandler.php(46): OC\AppFramework\App::main('RegisterControl...', 'validateEmail', Object(OC\AppFramework\DependencyInjection\DIContainer), Array) #6 [internal function]: OC\AppFramework\Routing\RouteActionHandler->__invoke(Array) #7 /home/www/fshareit.com/fshareit/lib/private/Route/Router.php(280): call_user_func(Object(OC\AppFramework\Routing\RouteActionHandler), Array) #8 /home/www/fshareit.com/fshareit/lib/base.php(891): OC\Route\Router->match('/apps/registrat...') #9 /home/www/fshareit.com/fshareit/index.php(54): OC::handleRequest() #10 {main} ownCloud

from registration.

Please check your mail server log, the problem doesn't look like having anything to do with registration.
Also, test if you can send email properly with "Send test email" in admin settings.

from registration.

I'm running into the same issue and tested the "Send test email" per your request. I have no issues with that per receiving the test e-mail.

Nextcloud 11 (Stable)
Registration v0.2.3
Apache v2.4.18
Redis v3.2.6

Side note. The first time, I was able to send the e-mail and received an "email has been sent" message on the site. I checked my e-mail but never received anything.

The "A problem occurred sending email, please contact your administrator." didn't start appearing until after the second time I tried sending the registration link e-mail. Not sure if this helps.

from registration.

So it seems like your mail server fail intermittently, you can try sending the test email a few more times and I guess it will fail for some times.
This is unlikely registration app's issue since it's using the same function to send emails with NC core. Closing the issue for now, reopen if you're sure registration emails always fail while NC test email always succeed.

from registration.