Laravel sending each e-mail multiple times - php

Question

When a certain event is fired, my Laravel based app has to send exactly one transactional email to each user in a mailing list.
Here is the loop code:
$users = User::where('notifiable', 1)->get();
foreach($users as $user) {
$info = [
'email' => $user->email,
'name' => $user->name
];
$data = [
'message' => 'Sample text'
];
Mail::send(['emails.html.notification', 'emails.text.notification',], $data, function($message) use ($info) {
$message
->to($info['email'], $info['name'])
->subject('example')
->from('admin#example.com','Example');
});
}
Unfortunately, several users are receiving the same mail multiple times.
I can't figure out what's happening:
When redirecting the emails to log, I see exactly one mail for each user as expected;
Every other events trigger emails to be sent to a single user. However, no one has received multiple emails from these events.
The app is using Sendinblue as an external SMTP service.
Some hints I got:
The hourly mail quota was very low -> the email were received 3 times (and the queue on Sendinblue was immediately filled)
The hourly mail quota was raised 10x -> no more queues on Sendinblue, but now users are receiving the same email up to 7 times!

Answer 1

Apparently, queuing the email and setting a delayed event has solved the problem.
Now a new job is requested every 10 seconds.
$users = User::where('notifiable', 1)->get();
$counter = 0;
foreach($users as $user) {
$payload = [
'email' => $user->email,
'name' => $user->name,
'message' => 'Sample text'
];
dispatch(new SendNotification($payload))
->delay(now()->addSeconds($counter * 10));
$counter++;
}
Thanks for your support!