This is because windows does not have a mail server installed by default.
The PHP mail() function just passes a mail to the local mail server, it does not actually do the mailing itself.
I am not familiar with mybb but if it can only use the PHP mail() function then you will need to install a mail server. I personally use
hMailServer but that does involve a little experience with mail servers or some trial and error.
Alternatively if mybb can be configured to use phpMailer that may also be an option.
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(Windows 10 Pro 64bit) (Wampserver 3.3.4 64bit) Aestan Tray Menu 3.2.5.4
<Apache versions MULTIPE> <PHP versions MULTIPLE> <MySQL Versions MULTIPLE>
<MariaDB versions MULTIPLE> <phpMyAdmin versions MULTIPLE> <MySQL Workbench 8.0.23>Read The Manuals Apache --
MySQL --
PHP --
phpMyAdminGet your Apache/MySQL/mariaDB/PHP ADDONs here from the
WAMPServer alternate Repo-X-X-X-
Backup your databases regularly Here is How dont regret it later! Yes even when developing -X-X-X-